path: root/doc/PG-adapting.texi

\def\fontdefs{\psfamily{bsf}{r}{c}{b}{b}{ri}{ri}{ro}{bo}\def\mainmagstep{1200}}
\input texinfo
@c TODO: setting for configuring proof hidden regions.
@c
@c
@c $Id$
@c
@c NB: the first line of this file uses a non-standard TeXinfo
@c hack to print in Serifa fonts.  It has no effect if you don't have
@c my hacked version of TeXinfo - da.
@c
@c 
@setfilename PG-adapting.info
@settitle Adapting Proof General
@setchapternewpage odd
@paragraphindent 0
@c A flag for whether to include the front image in the
@c DVI file.  You can download the front image from
@c http://www.proofgeneral.org/ProofGeneralPortrait.eps.gz
@c then put it into this directory and 'make dvi' (pdf,ps)
@c will set the flag below automatically.
@clear haveeps
@iftex
@afourpaper
@end iftex

@c
@c Some URLs.
@c FIXME: unfortunately, broken in buggy pdftexinfo.
@c so removed for now.
@set URLxsymbol  http://x-symbol.sourceforge.net/
@set URLisamode  http://zermelo.dcs.ed.ac.uk/~isamode
@set URLpghome   http://www.proofgeneral.org
@set URLpglatestrpm  http://www.proofgeneral.org/ProofGeneral-latest.noarch.rpm
@set URLpglatesttar  http://www.proofgeneral.org/ProofGeneral-latest.tar.gz
@set URLpglatestdev  http://www.proofgeneral.org/ProofGeneral-devel-latest.tar.gz
@c
@c

@c
@c IMPORTANT NOTE ABOUT THIS TEXINFO FILE:
@c I've tried keep full node lines *out* of this file because Emacs makes a
@c mess of updating them and they are a nuisance to do by hand.  
@c Instead, rely on makeinfo and friends to do the equivalent job.  
@c For this to work, we must follow each node
@c immediately with a section command, i.e.:
@c
@c  @node node-name
@c  <section-command>
@c
@c And each section with lower levels must have a menu command in
@c it.  Menu updating with Emacs is a bit better than node updating,
@c but tends to delete the first section of the file in XEmacs!
@c (it's better in GNU Emacs at the time of writing).
@c
@c
@c reminder about references: 
@c        @xref{node}  blah         start of sentence: See [ref]
@c        blah (@pxref{node}) blah  bla (see [ref]), best at end of sentence
@c        @ref{node}                without "see". Careful for info.


@set version 3.3
@set xemacsversion 21.4
@set fsfversion 20.7
@set last-update September 2001
@set rcsid $Id$

@ifinfo
@format
START-INFO-DIR-ENTRY 
* Proof General Adapting: (PG-adapting). How to adapt Proof General for new provers
END-INFO-DIR-ENTRY
@end format
@end ifinfo

@c
@c MACROS
@c
@c define one here for a command with a key-binding?
@c
@c I like the idea, but it's maybe against the TeXinfo
@c style to fix together a command and its key-binding.
@c
@c merge functions and variables into concept index.
@c @syncodeindex fn cp
@c @syncodeindex vr cp

@c merge functions into variables index
@c @syncodeindex fn vr

@finalout
@titlepage
@title Adapting Proof General
@subtitle Proof General --- Organize your proofs!
@sp 1
@subtitle Adapting Proof General @value{version} to new provers
@subtitle @value{last-update}
@subtitle @b{www.proofgeneral.org}

@c nested ifs fail here completely, WHY?
@iftex
@ifset haveeps
@c @vskip 1cm
@c The .eps file takes 8.4M!  A pity texi can't seem
@c to deal with gzipped files? (goes down to 1.7M).
@c But this still seems too much to put into the
@c PG distribution just for an image on the manual page,
@c so we take it out for now.
@c Ideally would like some way of generating eps from
@c the .jpg file.   
@c image{ProofGeneralPortrait}
@end ifset
@end iftex
@author David Aspinall with T. Kleymann
@page
@vskip 0pt plus 1filll
This manual and the program Proof General are
Copyright @copyright{} 2000,2001 Proof General team, LFCS Edinburgh.


@c
@c COPYING NOTICE
@c
@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission notice
identical to this one except for the removal of this paragraph (this
paragraph not being relevant to the printed manual).
@end ignore

@sp 2
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.  
@sp 2

This manual documents Proof General, Version @value{version}, for use
with XEmacs @value{xemacsversion} and GNU Emacs @value{fsfversion}
or later versions.

Visit Proof General on the web at @code{http://www.proofgeneral.org}

Version control: @code{@value{rcsid}}
@end titlepage

@page


@ifinfo
@node Top
@top Proof General

This file documents configuration mechanisms for version @value{version}
of @b{Proof General}, a generic Emacs interface for proof assistants.

Proof General @value{version} has been tested with XEmacs
@value{xemacsversion} and GNU Emacs @value{fsfversion}.  It is
supplied ready customized for the proof assistants Coq, Lego, 
Isabelle, and HOL.  

This manual contains information for customizing to new proof
assistants; see the user manual for details about how to use
Proof General.

@menu
* Introduction::
* Beginning with a new prover::
* Menus and toolbar and user-level commands::  
* Proof script settings::       
* Proof shell settings::        
* Goals buffer settings::  
* Splash screen settings::      
* Global constants::            
* Handling multiple files::     
* Configuring Font Lock::
* Configuring X-Symbol::
* Writing more lisp code::
* Internals of Proof General::  
* Plans and ideas::             
* Demonstration Instantiations::
* Function Index::              
* Variable Index::              
* Concept Index::               
@end menu
@end ifinfo

@node Introduction
@unnumbered Introduction

Welcome to Proof General!

Proof General a generic Emacs-based interface for proof assistants.

This manual contains information for adapting Proof General to new proof
assistants, and some sketches of the internal implementation.  It is not
intended for most ordinary users of the system.  
For full details about how to use Proof General, and information on its
availability and installation, please see the main Proof General manual
which should accompany this one.

We positively encourage the support of new systems.  Proof General has
grown more flexible and useful as it has been adapted to more proof
assistants.  

Typically, adding support for a new prover improves support for others,
both because the code becomes more robust, and because new ideas are
brought into the generic setting.  Notice that the Proof General
framework has been built as a "product line architecture": generality
has been introduced step-by-step in a demand-driven way, rather than at
the outset as a grand design.  Despite this strategy, the interface has
a surprisingly clean structure.  The approach means that we fully expect
hiccups when adding support for new assistants, so the generic core may
need extension or modification.  To support this we have an open
development method: if you require changes in the generic support,
please contact us (or make adjustments yourself and send them to us).

Proof General has a home page at
@uref{http://www.proofgeneral.org}.  Visit this page
for the latest version of the manuals, other documentation, system
downloads, etc.


@menu
* Future::
* Credits::
@end menu

@node Future
@unnumberedsec Future
@cindex Proof General Kit
@cindex Future

The aim of the Proof General project is to provide a powerful and
configurable interfaces which help user-interaction with interactive
proof assistants.  

The strategy Proof General uses is to targets power users rather than
novices; other interfaces have often neglected this class of users.  But
we do include general user interface niceties, such as toolbar and
menus, which make use easier for all.

Proof General has been Emacs based so far, but plans are afoot to
liberate it from the points and parentheses of Emacs Lisp.  The
successor project Proof General Kit proposes that proof assistants use a
@i{standard} XML-based protocol for interactive proof, dubbed @b{PGIP}.

PGIP enables middleware for interactive proof tools and interface
components.  Rather than configuring Proof General for your proof
assistant, you will need to configure your proof assistant to understand
PGIP.  There is a similarity however; the design of PGIP was based
heavily on the Emacs Proof General framework.  This means that effort on
customizing Emacs Proof General to a new proof assistant is worthwhile
even in the light of PGIP: it will help you to understand Proof
General's model of interaction, and moreover, we hope to use the Emacs
customizations to provide experimental filters which allow supported
provers to communicate using PGIP.

At the time of writing, these ideas are in early stages. For latest
details, or to become involved, see
@uref{http://www.proofgeneral.org/kit, the Proof General Kit
webpage}.


@node Credits
@unnumberedsec Credits

David Aspinall put together and wrote most of this manual.  Thomas
Kleymann wrote some of the text in Chapter 8.  Much of the content is
generated automatically from Emacs docstrings, some of which have been
written by other Proof General developers.



@node Beginning with a new prover
@chapter Beginning with a new prover

Proof General has about 100 configuration variables which are set on a
per-prover basis to configure the various features.  It may sound like a
lot but don't worry!  Many of the variables occur in pairs (typically
regular expressions matching the start and end of some text), and you
can begin by setting just a fraction of the variables to get the basic
features of script management working.  The bare minimum for a working
prototype is about 25 simple settings.

For more advanced features you may need (or want) to write some Emacs
Lisp.  If you're adding new functionality please consider making it
generic for different proof assistants, if appropriate.  When writing
your modes, please follow the Emacs Lisp conventions @inforef{Style
Tips, ,lispref}.

The configuration variables are declared in the file
@file{generic/proof-config.el}.  The details in the central part of this
manual are based on the contents of that file, beginning in @ref{Menus and toolbar
and user-level commands}, and continuing until @ref{Global constants}.
Other chapters cover the details of configuring for multiple files and
for supporting the other Emacs packages mentioned in the user manual
(@i{Support for other Packages}).  If you write additional Elisp code
interfacing to Proof General, you can find out about some useful functions
by reading @ref{Writing more lisp code}.  The last chapter of this
manual describes some of the internals of Proof General, in case you are
interested, maybe because you need to extend the generic core to do
something new.

In the rest of this chapter we describe the general mechanisms for
instantiating Proof General.  We assume some knowledge of the content
of the main Proof General manual.

@menu
* Overview of adding a new prover::            
* Demonstration instance and easy configuration::
* Major modes used by Proof General::  
@end menu


@node Overview of adding a new prover
@section Overview of adding a new prover

Each proof assistant supported has its own subdirectory under
@code{proof-home-directory}, used to store a root elisp file and any
other files needed to adapt the proof assistant for Proof General.

@c Here we show how a minimal configuration of Proof General works for
@c Isabelle, without any special changes to Isabelle.

Here is how to go about adding support for a new prover.

@enumerate
@item Make a directory called @file{myassistant/} under the Proof General home
directory @code{proof-home-directory}, to put the specific customization
and associated files in.
@item Add a file @file{myassistant.el} to the new directory.
@item Edit @file{proof-site.el} to add a new entry to the
  @code{proof-assistants-table} variable.  The new entry should look
like this:
@lisp
    (myassistant "My Proof Assistant" "\\.myasst$")
@end lisp    
The first item is used to form the name of the internal variables for
the new mode as well as the directory and file where it loads from.  The
second is a string, naming the proof assistant.  The third item is a
regular expression to match names of proof script files for this
assistant.  See the documentation of @code{proof-assistant-table} for
more details.
@item Define the new Proof General modes in @file{myassistant.el}, 
 by setting configuration variables to customize the
 behaviour of the generic modes.  
@end enumerate

@c You could begin by setting a minimum number of the variables, then
@c adjust the settings via the customize menus, under Proof-General ->
@c Internals.

@c TEXI DOCSTRING MAGIC: proof-assistant-table
@defopt proof-assistant-table 
Proof General's table of supported proof assistants.@*
Extend this table to add a new proof assistant.
Each entry is a list of the form
@lisp
    (@var{symbol} @var{name} @var{automode-regexp})
@end lisp
The @var{name} is a string, naming the proof assistant.
The @var{symbol} is used to form the name of the mode for the
assistant, @samp{SYMBOL-mode}, run when files with @var{automode-regexp}
are visited.  @var{symbol} is also used to form the name of the
directory and elisp file for the mode, which will be
@lisp
    @var{proof-home-directory}/@var{symbol}/@var{symbol}.el
@end lisp
where @samp{PROOF-HOME-DIRECTORY} is the value of the
variable @code{proof-home-directory}.

The default value is @code{((demoisa "Isabelle Demo" "\\.ML$") (isar "Isabelle/Isar" "\\.thy$") (isa "Isabelle" "\\.ML$\\|\\.thy$") (lego "LEGO" "\\.l$") (coq "Coq" "\\.v$") (phox "PhoX" "\\.phx$") (hol98 "HOL" "\\.sml$") (acl2 "ACL2" "\\.acl2$") (plastic "Plastic" "\\.lf$") (twelf "Twelf" "\\.elf$"))}.
@end defopt


The final step of the description above is where the work lies.  There
are two basic methods.  You can write some Emacs lisp functions and
define the modes using the macro @code{define-derived-mode}.  Or you can
use the new easy configuration mechanism of Proof General 3.0 described
in the next section, which calls @code{define-derived-mode} for you.
You still need to know which configuration variables should be set, and
how to set them.  

The documentation below (and inside Emacs) should help with that, but
the best way to begin might be to use an existing Proof General instance
as an example.  


@node Demonstration instance and easy configuration
@section Demonstration instance and easy configuration

Proof General is supplied with a demonstration instance for Isabelle
which configures the basic features.  This is a whittled down version of
Isabelle Proof General, which you can use as a template to get support
for a new assistant going.  Check the directory @file{demoisa} for the
two files @file{demoisa.el} and @file{demoisa-easy.el}.

The file @file{demoisa.el} follows the scheme described in @ref{Major
modes used by Proof General}.  It uses the Emacs Lisp macro
@code{define-derived-mode} to define the four modes for a Proof General
instance, by inheriting from the generic code.  Settings which configure
Proof General are made by functions called from within each mode, as
appropriate.

The file @file{demoisa-easy.el} uses a new simplified mechanism to
achieve (virtually) the same result.  It uses the macro
@code{proof-easy-config} defined in @file{proof-easy-configl.el} to make
all of the settings for the Proof General instance in one go, defining
the derived modes automatically using a regular naming scheme.  No lisp
code is used in this file except the call to this macro.  The minor
difference in the end result is that all the variables are set at once,
rather than inside each mode.  But since the configuration variables are
all global variables anyway, this makes no real difference.

The macro @code{proof-easy-config} is called like this:
@lisp
   (proof-easy-config @var{myprover} "@var{MyProver}"
        @var{config_1} @var{val_1}
        ...
        @var{config_n} @var{val_n})
@end lisp
The main body of the macro call is like the body of a @code{setq}.  It
contains pairs of variables and value settings.  The first argument to
the macro is a symbol defining the mode root, the second argument is a
string defining the mode name.  These should be the same as the first
part of the entry in @code{proof-assistant-table} for your prover.
@xref{Overview of adding a new prover}.  After the call to
@code{proof-easy-config}, the new modes @code{@var{myprover}-mode},
@code{@var{myprover}-shell-mode}, @code{@var{myprover}-response-mode},
and @code{@var{myprover}-goals-mode} will be defined.  The configuration
variables in the body will be set immediately.


This mechanism is in fact recommended for new instantiations of
Proof General since it follows a regular pattern, and we can more
easily adapt it in the future to new versions of Proof General.

Even Emacs Lisp experts should prefer the simplified mechanism.  If you
want to set some buffer-local variables in your Proof General modes, or
invoke supporting lisp code, this can easily be done by adding functions
to the appropriate mode hooks after the @code{proof-easy-config} call.
For example, to add extra settings for the shell mode for
@code{demoisa}, we could do this:
@lisp
   (defun demoisa-shell-extra-config ()
      @var{extra configuration ...}
    )
   (add-hook 'demoisa-shell-mode-hook 'demoisa-shell-extra-config)
@end lisp
The function to do extra configuration @code{demoisa-shell-extra-config}
is then called as the final step when @code{demoisa-shell-mode} is
entered (be wary, this will be after the generic
@code{proof-shell-config-done} is called, so it will be too late to set
normal configuration variables which may be examined by
@code{proof-shell-config-done}).


@node Major modes used by Proof General
@section Major modes used by Proof General

There are four major modes used by Proof General, one for each type of
buffer it handles.  The buffer types are: script, shell, response and
goals.  Each of these has a generic mode, respectively:
@code{proof-mode}, @code{proof-shell-mode}, @code{proof-response-mode},
and @code{proof-goals-mode}.

The pattern for defining the major mode for an instance of Proof General
is to use @code{define-derived-mode} to define a specific mode to inherit from
each generic one, like this:
@lisp
(define-derived-mode myass-shell-mode proof-shell-mode
   "MyAss shell" nil
   (myass-shell-config)
   (proof-shell-config-done))
@end lisp
Where @code{myass-shell-config} is a function which sets the
configuration variables for the shell (@pxref{Proof shell settings}).

It's important that each of your modes invokes one of the functions
 @code{proof-config-done},
 @code{proof-shell-config-done}, 
 @code{proof-response-config-done}, or
 @code{proof-goals-config-done}
once it has set its configuration variables.  These functions
finalize the configuration of the mode.

For each mode, there is a configuration variable which names it so that
Proof General can set buffers to the proper mode, or find buffers in
that mode.  These are documented below, and set like this:
@lisp
  (setq proof-mode-for-script 'myass-mode)
@end lisp
where @code{myass-mode} is your major mode for scripts, derived from
@code{proof-mode}.  You must set these variables before the proof shell
is started; one way to do this is inside a function which is called from
the hook @code{pre-shell-start-hook}.  See the file @file{demoisa.el}
for details of how to do this.

For future instantiations, it is recommended to follow the standard
scheme: @code{@var{PA}-mode}, @code{@var{PA}-shell-mode}, etc.

@c TEXI DOCSTRING MAGIC: proof-mode-for-script
@defvar proof-mode-for-script 
Mode for proof script buffers.@*
This is used by Proof General to find out which buffers 
contain proof scripts.
The regular name for this is <PA>-mode.  If you use any of the
convenience macros Proof General provides for defining commands
etc, then you should stick to this name.
Suggestion: this can be set in the script mode configuration.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-shell
@defvar proof-mode-for-shell 
Mode for proof shell buffers.@*
Usually customised for specific prover.
Suggestion: this can be set a function called by @samp{@code{proof-pre-shell-start-hook}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-response
@defvar proof-mode-for-response 
Mode for proof response buffer (and trace buffer, if used).@*
Usually customised for specific prover.
Suggestion: this can be set a function called by @samp{@code{proof-pre-shell-start-hook}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-mode-for-goals
@defvar proof-mode-for-goals 
Mode for proof state display buffers.@*
Usually customised for specific prover.
Suggestion: this can be set a function called by @samp{@code{proof-pre-shell-start-hook}}.
@end defvar

@node Menus and toolbar and user-level commands
@chapter Menus, toolbar, and user-level commands

The variables described in this chapter configure the menus, toolbar,
and user-level commands.  They should be set in the script mode
before @code{proof-config-done} is called.  (Toolbar configuration must
be made before @file{proof-toolbar.el} is loaded, which usually is
triggered automatically by an attempt to display the toolbar).

@menu
* Settings for generic user-level commands::
* Menu configuration::
* Toolbar configuration::
@end menu

@node Settings for generic user-level commands
@section Settings for generic user-level commands

@c TEXI DOCSTRING MAGIC: proof-assistant-home-page
@defvar proof-assistant-home-page 
Web address for information on proof assistant.@*
Used for Proof General's help menu.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-context-command
@defvar proof-context-command 
Command to display the context in proof assistant.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-info-command
@defvar proof-info-command 
Command to ask for help or information in the proof assistant.@*
String or fn.  If a string, the command to use. 
If a function, it should return the command string to insert.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-showproof-command
@defvar proof-showproof-command 
Command to display proof state in proof assistant.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-command
@defvar proof-goal-command 
Command to set a goal in the proof assistant.  String or fn.@*
If a string, the format character @samp{%s} will be replaced by the
goal string. 
If a function, it should return the command string to insert.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-save-command
@defvar proof-save-command 
Command to save a proved theorem in the proof assistant.  String or fn.@*
If a string, the format character @samp{%s} will be replaced by the
theorem name. 
If a function, it should return the command string to insert.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-find-theorems-command
@defvar proof-find-theorems-command 
Command to search for a theorem containing a given term. String or fn.@*
If a string, the format character @samp{%s} will be replaced by the term.
If a function, it should return the command string to insert.
@end defvar



@node Menu configuration
@section Menu configuration

As well as the generic Proof General menu, each proof assistant is
provided with a specific menu which can have prover-specific commands.
Proof General puts some default things on this menu, including the
commands to start/stop the prover, and the user-extensible "Favourites"
menu.

@c TEXI DOCSTRING MAGIC: PA-menu-entries
@defvar PA-menu-entries 
Extra entries for proof assistant specific menu. @*
A list of menu items [@var{name} @var{callback} @var{enabler} ...].  See the documentation
of @samp{@code{easy-menu-define}} for more details.
@end defvar

@c TEXI DOCSTRING MAGIC: PA-help-menu-entries
@defvar PA-help-menu-entries 
Extra entries for help submenu for proof assistant specific help menu.@*
A list of menu items [@var{name} @var{callback} @var{enabler} ...].  See the documentation
of @samp{@code{easy-menu-define}} for more details.
@end defvar


@node Toolbar configuration
@section Toolbar configuration

Unlike the menus, Proof General has only one toolbar.  For the "generic"
aspect of Proof General to work well, we shouldn't change (the meaning
of) the existing toolbar buttons too far.  This would discourage people
from experimenting with different proof assistants when they don't
really know them, which is one of the advantages that Proof General
brings.

But in case it is hard to map some of the generic buttons
onto functions in particular provers, and to allow extra
buttons, there is a mechanism for adjustment.

I used The Gimp to create the buttons for Proof General.  The
development distribution includes a button blank and some notes in
@file{etc/notes.txt} about making new buttons.


@c TEXI DOCSTRING MAGIC: proof-toolbar-entries-default
@defvar proof-toolbar-entries-default 
Example value for proof-toolbar-entries.  Also used to define Scripting menu.@*
This gives a bare toolbar that works for any prover, providing the
appropriate configuration variables are set.
To add/remove prover specific buttons, adjust the @samp{<PA>-toolbar-entries} 
variable, and follow the pattern in @samp{@code{proof-toolbar}.el} for 
defining functions, images.
@end defvar

@c TEXI DOCSTRING MAGIC: PA-toolbar-entries
@defvar PA-toolbar-entries 
List of entries for Proof General toolbar and Scripting menu.@*
Format of each entry is (@var{token} @var{menuname} @var{tooltip} @var{dynamic-enabler-p} @var{enable}).

For each @var{token}, we expect an icon with base filename @var{token},
a function proof-toolbar-<TOKEN>, and (optionally) a dynamic enabler 
proof-toolbar-<TOKEN>-enable-p.

If @var{enablep} is absent, item is enabled; if @var{enablep} is present, item
is only added to menubar and toolbar if @var{enablep} is non-null.

If @var{menuname} is nil, item will not appear on the scripting menu.

If @var{tooltip} is nil, item will not appear on the toolbar.

The default value is @samp{@code{proof-toolbar-entries-default}} which contains
the standard Proof General buttons.
@end defvar

Here's an example of how to remove a button, from @file{af2.el}:
@lisp
(setq af2-toolbar-entries
      (remassoc 'state af2-toolbar-entries))
@end lisp



@c defgroup proof-script
@node Proof script settings
@chapter Proof script settings

The variables described in this chapter should be set in the script mode
before @code{proof-config-done} is called.  These variables configure
recognition of commands in the proof script, and also control some of
the behaviour of script management.


@menu
* Recognizing commands and comments::
* Recognizing proofs::
* Recognizing other elements::
* Configuring undo behaviour::
* Nested proofs::
* Safe (state-preserving) commands::
* Activate scripting hook::
* Automatic multiple files::
* Completions::
@end menu


@node Recognizing commands and comments
@section Recognizing commands and comments

The first four settings configure the generic parsing strategy for
commands in the proof script.  Usually only one of these three needs to
be set.  If the generic parsing functions are not flexible for your
needs, you can supply a value for @code{proof-script-parse-function}.

Note that for the generic functions to work properly, it is
@strong{essential} that you set the syntax table for your mode properly,
so that comments and strings are recognized.  See the Emacs
documentation to discover how to do this (particularly for the function
@code{modify-syntax-entry}).

@xref{Proof script mode}, for more details of the parsing
functions.

@c TEXI DOCSTRING MAGIC: proof-terminal-char
@defvar proof-terminal-char 
Character which terminates every command sent to proof assistant.  nil if none.

To configure command recognition properly, you must set at least one
of these: @samp{@code{proof-script-sexp-commands}}, @samp{@code{proof-script-command-end-regexp}}, 
@samp{@code{proof-script-command-start-regexp}}, @samp{@code{proof-terminal-char}},
or @samp{@code{proof-script-parse-function}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-script-sexp-commands
@defvar proof-script-sexp-commands 
Non-nil if proof script has a LISP-like syntax, and commands are @code{top-level} sexps.@*
You should set this variable in script mode configuration.

To configure command recognition properly, you must set at least one
of these: @samp{@code{proof-script-sexp-commands}}, @samp{@code{proof-script-command-end-regexp}}, 
@samp{@code{proof-script-command-start-regexp}}, @samp{@code{proof-terminal-char}},
or @samp{@code{proof-script-parse-function}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-script-command-start-regexp
@defvar proof-script-command-start-regexp 
Regular expression which matches start of commands in proof script.@*
You should set this variable in script mode configuration.

To configure command recognition properly, you must set at least one
of these: @samp{@code{proof-script-sexp-commands}}, @samp{@code{proof-script-command-end-regexp}}, 
@samp{@code{proof-script-command-start-regexp}}, @samp{@code{proof-terminal-char}},
or @samp{@code{proof-script-parse-function}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-script-command-end-regexp
@defvar proof-script-command-end-regexp 
Regular expression which matches end of commands in proof script.@*
You should set this variable in script mode configuration.

To configure command recognition properly, you must set at least one
of these: @samp{@code{proof-script-sexp-commands}}, @samp{@code{proof-script-command-end-regexp}}, 
@samp{@code{proof-script-command-start-regexp}}, @samp{@code{proof-terminal-char}},
or @samp{@code{proof-script-parse-function}}.
@end defvar


The next four settings configure the comment syntax.  Notice that to get
reliable behaviour of the parsing functions, you may need to modify the
syntax table for your prover's mode.  Read the Elisp manual for details
about that.

@c TEXI DOCSTRING MAGIC: proof-comment-start
@defvar proof-comment-start 
String which starts a comment in the proof assistant command language.@*
The script buffer's @code{comment-start} is set to this string plus a space.
Moreover, comments are usually ignored during script management, and not
sent to the proof process.

You should set this variable for reliable working of Proof General,
as well as @samp{@code{proof-comment-end}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-comment-start-regexp

@defvar proof-comment-start-regexp 
Regexp which matches a comment start in the proof command language.

The default value for this is set as (@code{regexp-quote} @code{proof-comment-start})
but you can set this variable to something else more precise if necessary.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-comment-end
@defvar proof-comment-end 
String which ends a comment in the proof assistant command language.@*
The script buffer's @code{comment-end} is set to a space plus this string.
See also @samp{@code{proof-comment-start}}.

You should set this variable for reliable working of Proof General,
@end defvar

@c TEXI DOCSTRING MAGIC: proof-comment-end-regexp
@defvar proof-comment-end-regexp 
Regexp which matches a comment end in the proof command language.

The default value for this is set as (@code{regexp-quote} @code{proof-comment-end})
but you can set this variable to something else more precise if necessary.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-case-fold-search
@defvar proof-case-fold-search 
Value for @code{case-fold-search} when recognizing portions of proof scripts.@*
Also used for completion, via @samp{@code{proof-script-complete}}.
The default value is @samp{nil}.  If your prover has a case @strong{insensitive}
input syntax, @code{proof-case-fold-search} should be set to @samp{t} instead.  
NB: This setting is not used for matching output from the prover.
@end defvar


@node Recognizing proofs
@section Recognizing proofs

Up to three settings each may be supplied for recognizing goal-like and
save-like commands.  The @code{-with-hole-} settings are used to make a
record of the name of the theorem proved, and also to build a default
value for the rather complicated setting
@code{proof-script-next-entity-regexps}, which activates the @i{function
menu} feature.  

The @code{-p} subsidiary predicates were added to allow more
discriminating behaviour for particular proof assistants.  (This is a
typical example of where the core framework needs some additional
generalization, to simplify matters, and allow for a smooth handling of
nested proofs; the present state is only part of the way there).


@c TEXI DOCSTRING MAGIC: proof-goal-command-regexp
@defvar proof-goal-command-regexp 
Matches a goal command in the proof script.   @*
This is used (1) to make the default value for @samp{@code{proof-goal-command-p}},
used as an important part of script management to find the start
of an atomic undo block, and (2) to construct the default 
for @samp{@code{proof-script-next-entity-regexps}} used for function menus.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-goal-with-hole-regexp
@defvar proof-goal-with-hole-regexp 
Regexp which matches a command used to issue and name a goal.@*
The name of the theorem is build from the variable
@code{proof-goal-with-hole-result} using the same convention as 
@code{query-replace-regexp}. 
Used for setting names of goal..save regions and for default
@code{function-menu} configuration in @code{proof-script-find-next-entity}.

It's safe to leave this setting as nil.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-goal-command-p
@defvar proof-goal-command-p 
A function to test: is this really a goal command?

This is added as a more refined addition to @code{proof-goal-command-regexp},
to solve the problem that Coq and some other provers can have goals which 
look like definitions, etc.  (In the future we may generalize 
@code{proof-goal-command-regexp} instead).
@end defvar


@c TEXI DOCSTRING MAGIC: proof-save-command-regexp
@defvar proof-save-command-regexp 
Matches a save command.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-save-with-hole-regexp
@defvar proof-save-with-hole-regexp 
Regexp which matches a command to save a named theorem.@*
The name of the theorem is build from the variable
@code{proof-save-with-hole-result} using the same convention as 
@code{query-replace-regexp}. 
Used for setting names of goal..save and proof regions and for 
default @code{function-menu} configuration in @code{proof-script-find-next-entity}.

It's safe to leave this setting as nil.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-completed-proof-behaviour
@defvar proof-completed-proof-behaviour 
Indicates how Proof General treats commands beyond the end of a proof.@*
Normally goal...save regions are "closed", i.e. made atomic for undo.
But once a proof has been completed, there may be a delay before 
the "save" command appears --- or it may not appear at all.  Unless
nested proofs are supported, this can spoil the undo-behaviour in
script management since once a new goal arrives the old undo history
may be lost in the prover.  So we allow Proof General to close 
off the goal..[save] region in more flexible ways.  
The possibilities are:
@lisp
        nil  -  nothing special; close only when a save arrives
  @code{'closeany}  -  close as soon as the next command arrives, save or not
 @code{'closegoal}  -  close when the next "goal" command arrives
    @code{'extend}  -  keep extending the closed region until a save or goal.
@end lisp
If your proof assistant allows nested goals, it will be wrong to close
off the portion of proof so far, so this variable should be set to nil.
There is no built-in understanding of the undo behaviour of nested
proofs; instead there is some support for un-nesting nested proofs in
the @code{proof-lift-global} mechanism.  (Of course, this is risky in case of
nested contexts!)
@end defvar

@c TEXI DOCSTRING MAGIC: proof-really-save-command-p
@defvar proof-really-save-command-p 
Is this really a save command?

This is a more refined addition to @code{proof-save-command-regexp}.
It should be a function taking a span and command as argument,
and can be used to track nested proofs.  (See what is done in
isar/ for example). In the future, this setting should be
removed when the generic core is extended to handle nested
proofs smoothly.
@end defvar


@node Recognizing other elements
@section Recognizing other elements

To configure the @i{function menu} feature, there are a couple of
settings.  These can be used to recognize named proofs, and other
elements in the proof script as well.

@c TEXI DOCSTRING MAGIC: proof-script-next-entity-regexps
@defvar proof-script-next-entity-regexps 
Regular expressions to help find definitions and proofs in a script.@*
This is the list of the form
@lisp
   (@var{anyentity-regexp}
    @var{discriminator-regexp}  ... @var{discriminator-regexp})
@end lisp
The idea is that @var{anyentity-regexp} matches any named entity in the
proof script, on a line where the name appears.  This is assumed to be
the start or the end of the entity.  The discriminators then test
which kind of entity has been found, to get its name.  A
@var{discriminator-regexp} has one of the forms
@lisp
  (@var{regexp} @var{matchnos})
  (@var{regexp} @var{matchnos} @code{'backward} @var{backregexp})
  (@var{regexp} @var{matchnos} @code{'forward} @var{forwardregexp})
@end lisp
If @var{regexp} matches the string captured by @var{anyentity-regexp}, then
@var{matchnos} are the match numbers for the substrings which name the entity
(these may be either a single number or a list of numbers).

If @code{'backward} @var{backregexp} is present, then the start of the entity
is found by searching backwards for @var{backregexp}.

Conversely, if @code{'forward} @var{forwardregexp} is found, then the end of
the entity is found by searching forwards for @var{forwardregexp}.

Otherwise, the start and end of the entity will be the region matched
by @var{anyentity-regexp}.

This mechanism allows fairly complex parsing of the buffer, in
particular, it allows for goal..save regions which are named
only at the end.  However, it does not parse strings,
comments, or parentheses.

This variable may not need to be set: a default value which should
work for goal..saves is calculated from @code{proof-goal-with-hole-regexp},
@code{proof-goal-command-regexp}, and @code{proof-save-with-hole-regexp}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-script-find-next-entity-fn
@defvar proof-script-find-next-entity-fn 
Name of function to find next interesting entity in a script buffer.@*
This is used to configure @code{func-menu}.  The default value is
@code{proof-script-find-next-entity}, which searches for the next entity
based on fume-function-name-regexp which by default is set from
@code{proof-script-next-entity-regexps}.  

The function should move point forward in a buffer, and return a cons
cell of the name and the beginning of the entity's region.

Note that @code{proof-script-next-entity-regexps} is set to a default value
from @code{proof-goal-with-hole-regexp} and @code{proof-save-with-hole-regexp} in
the function @code{proof-config-done}, so you may not need to worry about any
of this.  See whether function menu does something sensible by
default.
@end defvar

@node Configuring undo behaviour
@section Configuring undo behaviour

The settings here are used to configure the way "undo" commands are
calculated.

@c TEXI DOCSTRING MAGIC: proof-non-undoables-regexp
@defvar proof-non-undoables-regexp 
Regular expression matching commands which are @strong{not} undoable.@*
Used in default functions @samp{@code{proof-generic-state-preserving-p}} 
and @samp{@code{proof-generic-count-undos}}.  If you don't use those,
may be left as nil.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-undo-n-times-cmd
@defvar proof-undo-n-times-cmd 
Command to undo n steps of the currently open goal.@*
String or function.
If this is set to a string, @samp{%s} will be replaced by the number of
undo steps to issue. 
If this is set to a function, it should return the appropriate
command when called with an integer (the number of undo steps).

This setting is used for the default @samp{@code{proof-generic-count-undos}}.
If you set @samp{@code{proof-count-undos-fn}} to some other function, there is no
need to set this variable.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-ignore-for-undo-count
@defvar proof-ignore-for-undo-count 
Matcher for script commands to be ignored in undo count.@*
May be left as nil, in which case it will be set to
@samp{@code{proof-non-undoables-regexp}}.
Used in default function @samp{@code{proof-generic-count-undos}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-count-undos-fn
@defvar proof-count-undos-fn 
Function to calculate a command to issue undos to reach a target span.@*
The function takes a span as an argument, and should return a string
which is the command to undo to the target span.  The target is
guaranteed to be within the current (open) proof.
This is an important function for script management.
The default setting @samp{@code{proof-generic-count-undos}} is based on the
settings @samp{@code{proof-non-undoables-regexp}} and
@samp{@code{proof-non-undoables-regexp}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-generic-count-undos
@defun proof-generic-count-undos span
Count number of undos in a span, return command needed to undo that far.@*
Command is set using @samp{@code{proof-undo-n-times-cmd}}.

A default value for @samp{@code{proof-count-undos-fn}}.

For this function to work properly, you must configure
@samp{@code{proof-undo-n-times-cmd}} and @samp{@code{proof-ignore-for-undo-count}}.
@end defun






@c TEXI DOCSTRING MAGIC: proof-find-and-forget-fn
@defvar proof-find-and-forget-fn 
Function that returns a command to forget back to before its argument span.@*
This setting is used to for retraction (undoing) in proof scripts.

It should undo the effect of all settings between its target span
up to (@code{proof-locked-end}).  This may involve forgetting a number
of definitions, declarations, or whatever.

The special string @code{proof-no-command} means there is nothing to do.

This is an important function for script management.
Study one of the existing instantiations for examples of how to write it,
or leave it set to the default function @samp{@code{proof-generic-find-and-forget}}
(which see).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-generic-find-and-forget
@defun proof-generic-find-and-forget span
Calculate a forget/undo command to forget back to @var{span}.@*
This is a long-range forget: we know that there is no
open goal at the moment, so forgetting involves unbinding
declarations, etc, rather than undoing proof steps.

This generic implementation assumes it is enough to find the 
nearest following span with a @samp{name} property, and retract
that using @samp{@code{proof-forget-id-command}} with the given name.

If this behaviour is not correct, you must customize the function
with something different.
@end defun

@c TEXI DOCSTRING MAGIC: proof-forget-id-command


@defvar proof-forget-id-command 
Command to forget back to a given named span.@*
A string; @samp{%s} will be replaced by the name of the span.

This is only used in the implementation of @samp{@code{proof-generic-find-and-forget}},
you only need to set if you use that function (by not customizing
@samp{@code{proof-find-and-forget-fn}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-goal-hyp-fn
@defvar proof-goal-hyp-fn 
Function which returns cons cell if point is at a goal/hypothesis.@*
This is used to parse the proofstate output to mark it up for
proof-by-pointing.  It should return a cons or nil.  First element of
the cons is a symbol, @code{'goal'} or @code{'hyp'}.  The second element is a
string: the goal or hypothesis itself.

If you leave this variable unset, no proof-by-pointing markup
will be attempted.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-kill-goal-command
@defvar proof-kill-goal-command 
Command to kill the currently open goal.@*
You must set this (perhaps to a no-op) for script management to work.
@end defvar



@node Nested proofs
@section Nested proofs

Proof General doesn't yet have a flexible understanding of
nested proofs, but can do something with them.

@c TEXI DOCSTRING MAGIC: proof-global-p
@defvar proof-global-p 
Whether a command is a global declaration.  Predicate on strings or nil.@*
This is used to handle nested goals allowed by some provers, by
recognizing global declarations as candidates for rearranging the
proof script.

May be left as nil to disable this function.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-lift-global
@defvar proof-lift-global 
Function which lifts local lemmas from inside goals out to top level.@*
This function takes the local goalsave span as an argument. Leave this
set this at @samp{nil} if the proof assistant does not support nested goals,
or if you don't want to write a function to do move them around.
@end defvar


@node Safe (state-preserving) commands
@section Safe (state-preserving) commands

A proof command is "safe" if it can be issued away from the proof
script.  For this to work it should be state-preserving in the proof
assistant (with respect to an on-going proof).

@c TEXI DOCSTRING MAGIC: proof-state-preserving-p
@defvar proof-state-preserving-p 
A predicate, non-nil if its argument (a command) preserves the proof state.@*
If set, used by @code{proof-minibuffer-cmd} to filter out scripting
commands which should be entered directly into the script itself.

The default setting for this function, @samp{@code{proof-generic-state-preserving-p}}
tests by negating the match on @samp{@code{proof-non-undoables-regexp}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-generic-state-preserving-p
@defun proof-generic-state-preserving-p cmd
Is @var{cmd} state preserving?  Match on @code{proof-non-undoables-regexp}.
@end defun


@node Activate scripting hook
@section Activate scripting hook


@c TEXI DOCSTRING MAGIC: proof-activate-scripting-hook
@defvar proof-activate-scripting-hook 
Hook run when a buffer is switched into scripting mode.@*
The current buffer will be the newly active scripting buffer.

This hook may be useful for synchronizing with the proof
assistant, for example, to switch to a new theory
(in case that isn't already done by commands in the proof
script).

When functions in this hook are called, the variable
@samp{activated-interactively} will be non-nil if 
@code{proof-activate-scripting} was called interactively
(rather than as a side-effect of some other action).
If a hook function sends commands to the proof process,
it should wait for them to complete (so the queue is cleared
for scripting commands), unless activated-interactively is set.
@end defvar


@node Automatic multiple files
@section Automatic multiple files

@xref{Handling multiple files}, for more details about this
setting.

@c TEXI DOCSTRING MAGIC: proof-auto-multiple-files
@defvar proof-auto-multiple-files 
Whether to use automatic multiple file management.@*
If non-nil, Proof General will automatically retract a script file
whenever another one is retracted which it depends on.  It assumes
a simple linear dependency between files in the order which
they were processed.

If your proof assistant has no management of file dependencies, or one
which depends on a simple linear context, you may be able to use this
setting to good effect.  If the proof assistant has more complex
file dependencies then you should configure it to communicate with
Proof General about the dependencies rather than using this setting.
@end defvar


@node Completions
@section Completions

Proof General allows provers to create a @i{completion table} to help
writing keywords and identifiers in proof scripts.  This is documented
in the main @i{Proof General} user manual but summarized here for (a
different kind of) completion.

Completions are filled in according to what has been recently typed,
from a database of symbols.  The database is automatically saved at the
end of a session.  Completion is usually a hand-wavy thing, so we don't
make any attempt to maintain a precise completion table or anything.

The completion table maintained by @file{complete.el} is initialized
from @code{PA-completion-table} when @file{proof-script.el} is loaded.
This is done with the function @code{proof-add-completions} which
you may want to call at other times.


@c TEXI DOCSTRING MAGIC: PA-completion-table
@defvar PA-completion-table 
List of identifiers to use for completion for this proof assistant.@*
Completion is activated with C-return.

If this table is empty or needs adjusting, please make changes using
@samp{@code{customize-variable}} and send suggestions to proofgen@@dcs.ed.ac.uk.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-add-completions
@deffn Command proof-add-completions 
Add completions from <PA>-completion-table to completion database.@*
Uses @samp{@code{add-completion}} with a negative number of uses and ancient
last use time, to discourage saving these into the users database.
@end deffn






@node Proof shell settings
@chapter Proof shell settings

The variables in this chapter concern the proof shell mode, and are the
largest group.  They are split into several subgroups.  The first
subgroup are commands invoked at various points.  The second subgroup of
variables are concerned with matching the output from the proof
assistant.  The final subgroup contains various hooks which you can set
to add lisp customization to Proof General in various points (some of
them are also used internally for behaviour you may wish to adjust).

Variables for configuring the proof shell are put into the customize
group @code{proof-shell}.

These should be set in the shell mode configuration, before
@code{proof-shell-config-done} is called.

To understand the way the proof assistant runs inside Emacs, you may
want to refer to the @code{comint.el} (Command interpreter) package
distributed with Emacs.  This package controls several shell-like modes
available in Emacs, including the @code{proof-shell-mode} and
all specific shell modes derived from it.

@menu
* Proof shell commands::
* Script input to the shell::
* Settings for matching various output from proof process::
* Settings for matching urgent messages from proof process::
* Hooks and other settings::  
@end menu

@node Proof shell commands
@section Commands

Settings in this section configure Proof General with commands
to send to the prover to activate certain actions.

@c TEXI DOCSTRING MAGIC: proof-prog-name
@defvar proof-prog-name 
System command to run the proof assistant in the proof shell.@*
Suggestion: this can be set in @code{proof-pre-shell-start-hook} from
a variable which is in the proof assistant's customization
group.  This allows different proof assistants to coexist
(albeit in separate Emacs sessions).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-auto-terminate-commands

@defvar proof-shell-auto-terminate-commands 
Non-nil if Proof General should try to add terminator to every command.@*
If non-nil, whenever a command is sent to the prover using
@samp{@code{proof-shell-invisible-command}}, Proof General will check to see if it
ends with @code{proof-terminal-char}, and add it if not.
If @code{proof-terminal-char} is nil, this has no effect.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-pre-sync-init-cmd
@defvar proof-shell-pre-sync-init-cmd 
The command for configuring the proof process to gain synchronization.@*
This command is sent before Proof General's synchronization
mechanism is engaged, to allow customization inside the process
to help gain syncrhonization (e.g. engaging special markup).

It is better to configure the proof assistant for this purpose
via command line options if possible, in which case this variable 
does not need to be set.

See also @samp{@code{proof-shell-init-cmd}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-init-cmd
@defvar proof-shell-init-cmd 
The command for initially configuring the proof process.@*
This command is sent to the process as soon as synchronization is gained
(when an annotated prompt is first recognized).  It can be used to configure 
the proof assistant in some way, or print a welcome message
(since output before the first prompt is discarded).

See also @samp{@code{proof-shell-pre-sync-init-cmd}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-restart-cmd
@defvar proof-shell-restart-cmd 
A command for re-initialising the proof process.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-quit-cmd
@defvar proof-shell-quit-cmd 
A command to quit the proof process.  If nil, send EOF instead.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-quit-timeout
@defvar proof-shell-quit-timeout 
The number of seconds to wait after sending @code{proof-shell-quit-cmd}.@*
After this timeout, the proof shell will be killed off more rudely.
If your proof assistant takes a long time to clean up (for
example writing persistent databases out or the like), you may
need to bump up this value.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-cd-cmd
@defvar proof-shell-cd-cmd 
Command to the proof assistant to change the working directory.@*
The format character @samp{%s} is replaced with the directory, and
the escape sequences in @samp{@code{proof-shell-filename-escapes}} are 
applied to the filename.

This setting is used to define the function @code{proof-cd} which 
changes to the value of (@code{default-directory}) for script buffers.
For files, the value of (@code{default-directory}) is simply the
directory the file resides in.

NB: By default, @code{proof-cd} is called from @code{proof-activate-scripting-hook},
so that the prover switches to the directory of a proof
script every time scripting begins.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-start-silent-cmd
@defvar proof-shell-start-silent-cmd 
Command to turn prover goals output off when sending many script commands.@*
If non-nil, Proof General will automatically issue this command
to help speed up processing of long proof scripts.  
See also @code{proof-shell-stop-silent-cmd}.
NB: terminator not added to command.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-stop-silent-cmd
@defvar proof-shell-stop-silent-cmd 
Command to turn prover output on.  @*
If non-nil, Proof General will automatically issue this command
to help speed up processing of long proof scripts.  
See also @code{proof-shell-start-silent-cmd}.
NB: Terminator not added to command.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-silent-threshold
@defvar proof-shell-silent-threshold 
Number of waiting commands in the proof queue needed to trigger silent mode.@*
Default is 2, but you can raise this in case switching silent mode
on or off is particularly expensive (or make it ridiculously large
to disable silent mode altogether).
@end defvar
@xref{Handling multiple files},
for more details about the final two settings in this group,


@c TEXI DOCSTRING MAGIC: proof-shell-inform-file-processed-cmd
@defvar proof-shell-inform-file-processed-cmd 
Command to the proof assistant to tell it that a file has been processed.@*
The format character @samp{%s} is replaced by a complete filename for a
script file which has been fully processed interactively with
Proof General.  See @samp{@code{proof-format-filename}} for other possibilities
to process the filename.

This setting used to interface with the proof assistant's internal
management of multiple files, so the proof assistant is kept aware of
which files have been processed.  Specifically, when scripting
is deactivated in a completed buffer, it is added to Proof General's
list of processed files, and the prover is told about it by
issuing this command.

If this is set to nil, no command is issued.

See also: @code{proof-shell-inform-file-retracted-cmd}, 
@code{proof-shell-process-file}, @code{proof-shell-compute-new-files-list}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-inform-file-retracted-cmd
@defvar proof-shell-inform-file-retracted-cmd 
Command to the proof assistant to tell it that a file has been retracted.@*
The format character @samp{%s} is replaced by a complete filename for a
script file which Proof General wants the prover to consider as not
completely processed.  See @samp{@code{proof-format-filename}} for other
possibilities to process the filename.

This is used to interface with the proof assistant's internal
management of multiple files, so the proof assistant is kept aware of
which files have been processed.  Specifically, when scripting
is activated, the file is removed from Proof General's list of 
processed files, and the prover is told about it by issuing this 
command.  The action may cause the prover in turn to suggest to 
Proof General that files depending on this one are
also unlocked.

If this is set to nil, no command is issued.

See also: @code{proof-shell-inform-file-processed-cmd}, 
@code{proof-shell-process-file}, @code{proof-shell-compute-new-files-list}.
@end defvar


@node Script input to the shell
@section Script input to the shell

Generally, commands from the proof script are sent verbatim to the proof
process running in the proof shell.  For historical reasons, carriage
returns are stripped by default.  You can set
@code{proof-shell-strip-crs-from-input} to adjust that.  For more
sophisticated pre-processing of the sent string, you may like to set
@code{proof-shell-insert-hook}.

@c TEXI DOCSTRING MAGIC: proof-shell-strip-crs-from-input 
@defvar proof-shell-strip-crs-from-input 
If non-nil, replace carriage returns in every input with spaces.@*
This is enabled by default: it is appropriate for some systems
because several CR's can result in several prompts, which may mess
up the display (or even worse, the synchronization).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-insert-hook
@defvar proof-shell-insert-hook 
Hooks run by @code{proof-shell-insert} before inserting a command.@*
Can be used to configure the proof assistant to the interface in
various ways -- for example, to observe or alter the commands sent to
the prover, or to sneak in extra commands to configure the prover.

This hook is called inside a @code{save-excursion} with the @code{proof-shell-buffer} 
current, just before inserting and sending the text in the 
variable @samp{string}.  The hook can massage @samp{string} or insert additional 
text directly into the @code{proof-shell-buffer}.  
Before sending @samp{string}, it will be stripped of carriage returns.

Additionally, the hook can examine the variable @samp{action}.  It will be
a symbol, set to the callback command which is executed in the proof
shell filter once @samp{string} has been processed.  The @samp{action} variable
suggests what class of command is about to be inserted:
@lisp
 @code{'proof-done-invisible}       A non-scripting command
 @code{'proof-done-advancing}       A "forward" scripting command
 @code{'proof-done-retracting}      A "backward" scripting command
@end lisp
Caveats: You should be very careful about setting this hook.  Proof
General relies on a careful synchronization with the process between
inputs and outputs.  It expects to see a prompt for each input it
sends from the queue.  If you add extra input here and it causes more
prompts than expected, things will break!  Extending the variable
@samp{string} may be safer than inserting text directly, since it is
stripped of carriage returns before being sent.

Example uses:
@var{lego} uses this hook for setting the pretty printer width if
the window width has changed;
Plastic uses it to remove literate-style markup from @samp{string}. 
The x-symbol support uses this hook to convert special characters
into tokens for the proof assistant.
@end defvar






@node Settings for matching various output from proof process
@section Settings for matching various output from proof process

These settings control the way Proof General reacts to process output.
The single most important setting is
@code{proof-shell-annotated-prompt-regexp}, which @b{must} be set as
part of the prover configuraton.  This is used to configure the
communication with the prover process.


@c TEXI DOCSTRING MAGIC: proof-shell-wakeup-char
@defvar proof-shell-wakeup-char 
A special character which terminates an annotated prompt.@*
Set to nil if proof assistant does not support annotated prompts.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-first-special-char
@defvar proof-shell-first-special-char 
First special character.@*
Codes above this character can have special meaning to Proof General,
and are stripped from the prover's output strings.
Leave unset if no special characters are being used.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-prompt-pattern
@defvar proof-shell-prompt-pattern 
Proof shell's value for comint-prompt-pattern, which see.@*
This pattern is just for interaction in comint (shell buffer).
You don't really need to set it.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-annotated-prompt-regexp
@defvar proof-shell-annotated-prompt-regexp 
Regexp matching a (possibly annotated) prompt pattern.

@var{this} IS THE @var{most} @var{important} @var{setting} TO @var{configure}!!   

Output is grabbed between pairs of lines matching this regexp,
and the appearance of this regexp is used by Proof General to
recognize when the prover has finished processing a command.

To help speed up matching you may be able to annotate the 
proof assistant prompt with a special character not appearing 
in ordinary output.  The special character should appear in 
this regexp, and should be the value of @code{proof-shell-wakeup-char}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-abort-goal-regexp
@defvar proof-shell-abort-goal-regexp 
Regexp matching output from an aborted proof.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-error-regexp
@defvar proof-shell-error-regexp 
Regexp matching an error report from the proof assistant.

We assume that an error message corresponds to a failure in the last
proof command executed.  So don't match mere warning messages with
this regexp.  Moreover, an error message should not be matched as an
eager annotation (see @code{proof-shell-eager-annotation-start}) otherwise it
will be lost.

Error messages are considered to begin from @code{proof-shell-error-regexp}
and continue until the next prompt.  The variable
@samp{@code{proof-shell-truncate-before-error}} controls whether text before the
error message is displayed.

The engine matches interrupts before errors, see @code{proof-shell-interrupt-regexp}.

It is safe to leave this variable unset (as nil).
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-interrupt-regexp
@defvar proof-shell-interrupt-regexp 
Regexp matching output indicating the assistant was interrupted.@*
We assume that an interrupt message corresponds to a failure in the last
proof command executed.  So don't match mere warning messages with
this regexp.  Moreover, an interrupt message should not be matched as an
eager annotation (see @code{proof-shell-eager-annotation-start}) otherwise it
will be lost.

The engine matches interrupts before errors, see @code{proof-shell-error-regexp}.

It is safe to leave this variable unset (as nil).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-truncate-before-error
@defvar proof-shell-truncate-before-error 
Non-nil means truncate output that appears before error messages.@*
If nil, the whole output that the prover generated before the last
error message will be shown.

NB: the default setting for this is @samp{t} to be compatible with
behaviour in Proof General before version 3.4.  The more obvious
setting for new instances is probably @samp{nil}.

Interrupt messages are treated in the same way.
See @samp{@code{proof-shell-error-regexp}} and @samp{@code{proof-shell-interrupt-regexp}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-proof-completed-regexp
@defvar proof-shell-proof-completed-regexp 
Regexp matching output indicating a finished proof.

When output which matches this regexp is seen, we clear the goals
buffer in case this is not also marked up as a @samp{goals} type of
message.

We also enable the QED function (save a proof) and will automatically
close off the proof region if another goal appears before a save
command.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-start-goals-regexp
@defvar proof-shell-start-goals-regexp 
Regexp matching the start of the proof state output.@*
This is an important setting.  Output between @samp{@code{proof-shell-start-goals-regexp}}
and @samp{@code{proof-shell-end-goals-regexp}} will be pasted into the goals buffer
and possibly analysed further for proof-by-pointing markup.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-end-goals-regexp
@defvar proof-shell-end-goals-regexp 
Regexp matching the end of the proof state output, or nil.@*
If nil, just use the rest of the output following @code{proof-shell-start-goals-regexp}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-assumption-regexp
@defvar proof-shell-assumption-regexp 
A regular expression matching the name of assumptions.

At the moment, this setting is not used in the generic Proof General.

In the future it will be used for a generic implementation for @samp{@code{proof-goal-hyp-fn}},
used to help parse the goals buffer to annotate it for proof by pointing.
@end defvar



@node Settings for matching urgent messages from proof process
@section Settings for matching urgent messages from proof process

Among the various dialogue messages that the proof assistant outputs
during proof, Proof General can consider certain messages to be
"urgent".  When processing many lines of a proof, Proof General will
normally supress the output, waiting until the final message appears
before displaying anything to the user.  Urgent messages escape this:
typically they include messages that the prover wants the user to
notice, for example, perhaps, file loading messages, or timing
statistics.

So that Proof General notices, these urgent messages should be marked-up
with "eager" annotations.

@c TEXI DOCSTRING MAGIC: proof-shell-eager-annotation-start
@defvar proof-shell-eager-annotation-start 
Eager annotation field start.  A regular expression or nil.@*
An eager annotation indicates to Proof General that some following output
should be displayed (or processed) immediately and not accumulated for 
parsing later. 

It is nice to recognize (starts of) warnings or file-reading messages
with this regexp.  You must also recognize any special messages
from the prover to PG with this regexp (e.g. @samp{@code{proof-shell-clear-goals-regexp}}, 
@samp{@code{proof-shell-retract-files-regexp}}, etc.)

See also @samp{@code{proof-shell-eager-annotation-start-length}},
@samp{@code{proof-shell-eager-annotation-end}}.

Set to nil to disable this feature.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-eager-annotation-start-length

@defvar proof-shell-eager-annotation-start-length 
Maximum length of an eager annotation start. @*
Must be set to the maximum length of the text that may match
@samp{@code{proof-shell-eager-annotation-start}} (at least 1).
If this value is too low, eager annotations may be lost!

This value is used internally by Proof General to optimize the process
filter to avoid unnecessary searching.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-eager-annotation-end
@defvar proof-shell-eager-annotation-end 
Eager annotation field end.  A regular expression or nil.@*
An eager annotation indicates to Emacs that some following output
should be displayed or processed immediately.

See also @samp{@code{proof-shell-eager-annotation-start}}.

It is nice to recognize (ends of) warnings or file-reading messages
with this regexp.  You must also recognize (ends of) any special messages
from the prover to PG with this regexp (e.g. @samp{@code{proof-shell-clear-goals-regexp}}, 
@samp{@code{proof-shell-retract-files-regexp}}, etc.)

The default value is "\n" to match up to the end of the line.
@end defvar


The default action for urgent messages is to display them in the
response buffer, highlighted.  But we also allow for some control
messages, issued from the proof assistant to Proof General and not
intended for the user to see.  These are recognized in the same way as
urgent messages (marked with eager annotations), so they will
be acted on as soon as they are issued by the prover.


@c TEXI DOCSTRING MAGIC: proof-shell-clear-response-regexp
@defvar proof-shell-clear-response-regexp 
Regexp matching output telling Proof General to clear the response buffer.@*
This feature is useful to give the prover more control over what output
is shown to the user.  Set to nil to disable.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-clear-goals-regexp
@defvar proof-shell-clear-goals-regexp 
Regexp matching output telling Proof General to clear the goals buffer.@*
This feature is useful to give the prover more control over what output
is shown to the user.  Set to nil to disable.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-set-elisp-variable-regexp
@defvar proof-shell-set-elisp-variable-regexp 
Regexp matching output telling Proof General to set some variable.@*
This allows the proof assistant to configure Proof General directly
and dynamically.  

If the regexp matches output from the proof assistant, there should be
two match strings: (@code{match-string} 1) should be the name of the elisp
variable to be set, and (@code{match-string} 2) should be the value of the
variable (which will be evaluated as a lisp expression).

A good markup for the second string is to delimit with #'s, since
these are not valid syntax for elisp evaluation.

Elisp errors will be trapped when evaluating; set 
@code{proof-show-debug-messages} to be informed when this happens.

Example uses are to adjust PG's internal copies of proof assistant's
settings, or to make automatic dynamic syntax adjustments in Emacs to
match changes in theory, etc.  

If you pick a dummy variable name (e.g. @samp{proof-dummy-setting}) you
can just evaluation arbitrary elisp expressions for their side
effects, to adjust menu entries, or even launch auxiliary programs.
But use with care -- there is no protection against catastrophic elisp!

This setting could also be used to move some configuration settings
from PG to the prover, but this is not really supported (most settings
must be made before this mechanism will work).  In future, the PG
standard protocol, @var{pgip}, will use this mechanism for making all
settings.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-theorem-dependency-list-regexp
@defvar proof-shell-theorem-dependency-list-regexp 
Regexp matching output telling Proof General what the dependencies are.  @*
This is so that the dependent theorems can be highlighted somehow.  
Set to nil to disable.
This is an experimental feature, currently work-in-progress.
@end defvar

Two important control messages are recognized by
@code{proof-shell-process-file} and
@code{proof-shell-retract-files-regexp}, used for synchronizing Proof
General with a file loading mechanism built into the proof assistant.
@xref{Handling multiple files}, for more details about how to use the
final three settings described here.

@vindex proof-included-files-list
@c TEXI DOCSTRING MAGIC: proof-shell-process-file
@defvar proof-shell-process-file 
A pair (@var{regexp} . @var{function}) to match a processed file name.

If @var{regexp} matches output, then the function @var{function} is invoked on the
output string chunk. It must return the name of a script file (with
complete path) that the system has successfully processed. In
practice, @var{function} is likely to inspect the match data.  If it returns
the empty string, the file name of the scripting buffer is used
instead.  If it returns nil, no action is taken.

Care has to be taken in case the prover only reports on compiled
versions of files it is processing. In this case, @var{function} needs to
reconstruct the corresponding script file name. The new (true) file
name is added to the front of @samp{@code{proof-included-files-list}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-retract-files-regexp
@defvar proof-shell-retract-files-regexp 
Matches a message that the prover has retracted a file.

At this stage, Proof General's view of the processed files is out of
date and needs to be updated with the help of the function
@samp{@code{proof-shell-compute-new-files-list}}.
@end defvar
@vindex proof-included-files-list

@c TEXI DOCSTRING MAGIC: proof-shell-compute-new-files-list
@defvar proof-shell-compute-new-files-list 
Function to update @samp{proof-included-files list}.

It needs to return an up to date list of all processed files. Its
output is stored in @samp{@code{proof-included-files-list}}. Its input is the
string of which @samp{@code{proof-shell-retract-files-regexp}} matched a
substring. In practice, this function is likely to inspect the
previous (global) variable @samp{@code{proof-included-files-list}} and the match
data triggered by @samp{@code{proof-shell-retract-files-regexp}}.
@end defvar



@node Hooks and other settings
@section Hooks and other settings

@c TEXI DOCSTRING MAGIC: proof-shell-filename-escapes
@defvar proof-shell-filename-escapes 
A list of escapes that are applied to %s for filenames.@*
A list of cons cells, car of which is string to be replaced
by the cdr.
For example, when directories are sent to Isabelle, HOL, and Coq,
they appear inside ML strings and the backslash character and
quote characters must be escaped.  The setting
@lisp
  '(("@var{\\\\}" . "@var{\\\\}")
    ("\"" . "\\\""))
@end lisp
achieves this.   This does not apply to @var{lego}, which does not
need backslash escapes and does not allow filenames with
quote characters.

This setting is used inside the function @samp{@code{proof-format-filename}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-process-connection-type
@defvar proof-shell-process-connection-type 
The value of @code{process-connection-type} for the proof shell.@*
Set non-nil for ptys, nil for pipes.
The default (and preferred) option is to use pty communication.
However there is a long-standing backslash/long line problem with
Solaris which gives a mess of ^G characters when some input is sent
which has a  in the 256th position.   
So we select pipes by default if it seems like we're on Solaris.
We do not force pipes everywhere because this risks loss of data.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-pre-shell-start-hook
@defvar proof-pre-shell-start-hook 
Hooks run before proof shell is started.@*
Suggestion: set this to a function which configures just these proof
shell variables: 
@lisp
   @code{proof-prog-name}
   @code{proof-mode-for-shell}
   @code{proof-mode-for-response}
   @code{proof-mode-for-goals}
   @code{proof-shell-trace-output-regexp}
@end lisp
This is the bare minimum needed to get a shell buffer and
its friends configured in the function @code{proof-shell-start}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-handle-error-or-interrupt-hook
@defvar proof-shell-handle-error-or-interrupt-hook 
Run after an error or interrupt has been reported in the response buffer.@*
Hook functions may inspect @samp{@code{proof-shell-error-or-interrupt-seen}} to 
determine whether the cause was an error or interrupt.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-pre-interrupt-hook
@defvar proof-shell-pre-interrupt-hook 
Run immediately after @samp{@code{comint-interrupt-subjob}} is called.@*
This hook is added to allow customization for Poly/ML and other
systems where the system queries the user before returning to
the top level.  For Poly/ML it can be used to send the string "f",
for example.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-process-output-system-specific
@defvar proof-shell-process-output-system-specific 
Set this variable to handle system specific output.@*
Errors, start of proofs, abortions of proofs and completions of
proofs are recognised in the function @samp{@code{proof-shell-process-output}}.
All other output from the proof engine is simply reported to the
user in the @var{response} buffer.

To catch further special cases, set this variable to a pair of
functions '(condf . actf). Both are given (cmd string) as arguments.
@samp{cmd} is a string containing the currently processed command.
@samp{string} is the response from the proof system. To change the
behaviour of @samp{@code{proof-shell-process-output}}, (condf cmd string) must
return a non-nil value. Then (actf cmd string) is invoked. 

See the documentation of @samp{@code{proof-shell-process-output}} for the required
output format.
@end defvar





@node Goals buffer settings
@chapter Goals buffer settings

The goals buffer settings allow configuration of Proof General for proof
by pointing or similar features.
See the Proof General @uref{http://www.proofgeneral.org/doc, documentation web page}
for a link to the technical report ECS-LFCS-97-368 which hints
at how to use these settings.

@c At the moment these settings are disabled.

@c TEXI DOCSTRING MAGIC: pbp-change-goal
@defvar pbp-change-goal 
Command to change to the goal @samp{%s}
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-goal-command
@defvar pbp-goal-command 
Command informing the prover that @samp{@code{pbp-button-action}} has been@*
requested on a goal.
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-hyp-command
@defvar pbp-hyp-command 
Command informing the prover that @samp{@code{pbp-button-action}} has been@*
requested on an assumption.
@end defvar
@c TEXI DOCSTRING MAGIC: pbp-error-regexp
@defvar pbp-error-regexp 
Regexp indicating that the proof process has identified an error.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-result-start
@defvar proof-shell-result-start 
Regexp matching start of an output from the prover after pbp commands.@*
In particular, after a @samp{@code{pbp-goal-command}} or a @samp{@code{pbp-hyp-command}}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-result-end
@defvar proof-shell-result-end 
Regexp matching end of output from the prover after pbp commands.@*
In particular, after a @samp{@code{pbp-goal-command}} or a @samp{@code{pbp-hyp-command}}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-start-char
@defvar proof-shell-start-char 
Starting special for a subterm markup.@*
Subsequent characters with values @strong{below} @code{proof-shell-first-special-char}
are assumed to be subterm position indicators.  Subterm markups should
be finished with @code{proof-shell-end-char}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-end-char
@defvar proof-shell-end-char 
Finishing special for a subterm markup.@*
See documentation of @code{proof-shell-start-char}.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-goal-char
@defvar proof-shell-goal-char 
Mark for goal.

This setting is also used to see if proof-by-pointing features
are configured.  If it is unset, some of the code 
for parsing the prover output is disabled.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-shell-field-char
@defvar proof-shell-field-char 
Annotated field end
@end defvar


@node Splash screen settings
@chapter Splash screen settings

The splash screen can be configured, in a rather limited way.

@c TEXI DOCSTRING MAGIC: proof-splash-time
@defvar proof-splash-time 
Minimum number of seconds to display splash screen for.@*
The splash screen may be displayed for a couple of seconds longer than
this, depending on how long it takes the machine to initialise 
Proof General.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-splash-contents
@defvar proof-splash-contents 
Evaluated to configure splash screen displayed when entering Proof General.@*
A list of the screen contents.  If an element is a string or an image
specifier, it is displayed centred on the window on its own line.  
If it is nil, a new line is inserted.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-splash-extensions
@defvar proof-splash-extensions 
Prover specific extensions of splash screen.@*
These are evaluated and appended to @samp{@code{proof-splash-contents}}.
@end defvar






@node Global constants
@chapter Global constants

The settings here are internal constants used by Proof General.
You don't need to configure these for your proof assistant
unless you want to modify or extend the defaults.

@c TEXI DOCSTRING MAGIC: proof-general-name
@defvar proof-general-name 
Proof General name used internally and in menu titles.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-general-home-page
@defopt proof-general-home-page 
Web address for Proof General

The default value is @code{"http://www.proofgeneral.org"}.
@end defopt
@c TEXI DOCSTRING MAGIC: proof-universal-keys
@defvar proof-universal-keys 
List of key-bindings made for the script, goals and response buffer. @*
Elements of the list are tuples @samp{(k . f)} 
where @samp{k} is a @code{key-binding} (vector) and @samp{f} the designated function.
@end defvar



@node Handling multiple files
@chapter Handling multiple files
@cindex Multiple files

Large proof developments are typically spread across multiple files.
Many provers support such developments by keeping track of dependencies
and automatically processing scripts. Proof General supports this
mechanism. The user's point of view is considered in the user manual.
Here, we describe the more technical nitty gritty.  This is what you
need to know when you customise another proof assistant to work with
Proof General.

Documentation for the configuration settings mentioned here appears in
the previous sections, this section is intended to help explain the use
of those settings.

Proof General maintains a list @code{proof-included-files-list} of files
which it thinks have been processed by the proof assistant.  When a file
which is on this list is visited in Emacs, it will be coloured entirely
blue to indicate that it has been processed.  No editing of the file
will be allowed (unless @code{proof-strict-read-only} allows it).


@c TEXI DOCSTRING MAGIC: proof-included-files-list
@defvar proof-included-files-list 
List of files currently included in proof process.@*
This list contains files in canonical truename format
(see @samp{@code{file-truename}}).

Whenever a new file is being processed, it gets added to this list
via the @code{proof-shell-process-file} configuration settings.
When the prover retracts a file, this list is resynchronised via the
@code{proof-shell-retract-files-regexp} and @code{proof-shell-compute-new-files-list} 
configuration settings.

Only files which have been @strong{fully} processed should be included here.
Proof General itself will automatically add the filenames of a script
buffer which has been completely read when scripting is deactivated.
It will automatically remove the filename of a script buffer which
is completely unread when scripting is deactivated.

NB: Currently there is no generic provision for removing files which
are only partly read-in due to an error, so ideally the proof assistant
should only output a processed message when a file has been successfully
read.
@end defvar

The way that @code{proof-included-files-list} is maintained is the key
to multiple file management.  (But you should not set this variable
directly, it is managed via the configuration settings).

@vindex proof-shell-process-file
@vindex proof-shell-retract-files-regexp
@vindex proof-shell-compute-new-files-list

There is a range of strategies for managing multiple files.  Ideally,
file dependencies should be managed by the proof assistant.  Proof
General will use the prover's low-level commands to process a whole file
and its requirements non-interactively, without going through script
management.  So that the user knows which files have been processed, the
proof assistant should issue messages which Proof General can recognize
(``file @code{foo} has been processed'') --- see
@code{proof-shell-process-file}.  When the user wants to edit a file
which has been processed, the file must be retracted (unlocked).  The
proof assistant should provide a command corresponding to this action,
which undoes a given file and all its dependencies.  As each file is
undone, a message should be issued which Proof General can recognize
(``file @code{foo} has been undone'') -- see
@code{proof-shell-retract-files-regexp}.  (The function
@code{proof-shell-compute-new-files-list} should be set to calculate the
new value for @code{proof-included-files-list} after a retract message
has been seen).


@c The key idea is that we leave it to the specific proof assistant to
@c worry about managing multiple files, as far as possible.  Whenever the
@c proof assistant processes or retracts a file it must clearly say so, so
@c that Proof General can register this.

As well as this communication from the assistant to Proof General about
processed or retracted files, Proof General can communicate the other
way: it will tell the proof assistant when it has processed or retracted
a file via script management.  This is because during script management,
the proof assistant may not be aware that it is actually dealing with a
file of proof commands (rather than just terminal input).

Proof General will provide this information in two special instances.
First, when scripting is turned off in a file that has been completely
processed, Proof General will tell the proof assistant using
@code{proof-shell-inform-file-processed-cmd}.  Second, when scripting is
turned on in a file which is completely processed, Proof General will
tell the proof assistant to reconsider: the file should not be
considered completely processed yet.  This uses the setting
@code{proof-shell-inform-file-retracted-cmd}.  This second case might
lead to a series of messages from the prover telling Proof General to
unlock files which depend on the present one, again via
@code{proof-shell-retract-files-regexp}.

What we have described so far is the ideal case, but it may require some
support from the proof assistant to set up (for example, if file-level
undo is not normally supported, or the messages during file processing
are not suitable).  Moreover, some proof assistants may not have file
handling with dependencies, or may have a particularly simple case of a
linear context: each file depends on all the ones processed before it.
Proof General allows you a shortcut to get automatic management of
multiple files in these cases by setting the flag
@code{proof-auto-multiple-files}.  This setting is probably an
approximation to the right thing for any proof assistant.  More files
than necessary will be retracted if the prover has a tree-like file
dependency rather than a linear one.

@vindex proof-shell-eager-annotation-start
@vindex proof-shell-eager-annotation-end
Finally, we should mention how Proof General recognizes file processing
messages from the proof assistant.  Proof General considers @var{output}
delimited by the the two regular expressions
@code{proof-shell-eager-annotation-start} and
@code{proof-shell-eager-annotation-end} as being important. It displays
the @var{output} in the Response buffer and analyses the contents
further. Among other important messages characterised by these regular
expressions (warnings, errors, or information), the prover can tell the
interface whenever it processes or retracts a file.


To summarize, the settings for multiple file management that may be
customized are as follows. To recognize file-processing,
@code{proof-shell-process-file}.  To recognize messages about file
undoing, @code{proof-shell-retract-files-regexp} and
@code{proof-shell-compute-new-files-list}.  @xref{Settings for matching
urgent messages from proof process}.  To tell the prover about files
handled with script management, use
 @code{proof-shell-inform-file-processed-cmd} and
 @code{proof-shell-inform-file-retracted-cmd}.  @xref{Proof shell
 commands}.  Finally, set the flag @code{proof-auto-multiple-files} 
for a automatic approximation to multiple file handling.
@xref{Proof script settings}.


@node Configuring Font Lock
@chapter Configuring Font Lock
@cindex font lock

Support for Font Lock in Proof General is described in the user manual
(see the @i{Syntax highlighting} section).  To configure Font Lock for a
new proof assistant, you need to set the variable
@code{font-lock-keywords} in each of the mode functions you want
highlighting for.  Proof General will automatically install these
settings, and enable Font Lock minor mode (for syntax highlighting as
you type) in script buffers.

@c nope: too big. TEXI DOCSTRING MAGIC: font-lock-keywords
To understand its format, check the documentation of
@code{font-lock-keywords} inside Emacs.

Proof General has a special hack for simplifying font lock settings
@code{proof-font-lock-zap-commas}, but it is recommended to restrict to
using the @code{font-lock-keywords} setting if possible.


@c TEXI DOCSTRING MAGIC: proof-font-lock-zap-commas
@defvar proof-font-lock-zap-commas 
If non-nil, enable a font-lock hack which unfontifies commas.@*
If you fontify variables inside lists like [a,b,c] by matching
on the brackets @samp{[} and @samp{]}, you may take objection to the commas 
being coloured as well.  In that case, enable this hack which
will magically restore the commas to the default font for you.

The hack is rather painful and forces immediate fontification of
files on loading (no lazy, caching locking).  It is unreliable
under GNU Emacs, to boot.

@var{lego} and Coq enable it by tradition.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-before-fontify-output-hook
@defvar proof-before-fontify-output-hook 
This hook is called before fonfitying a region in an output buffer.@*
This hook is mainly used by @code{phox-sym-lock}.
@end defvar


@node Configuring X-Symbol
@chapter Configuring X-Symbol
@cindex X-Symbol

The X-Symbol package is described in the Proof General user manual.  To
configure X-Symbol for Proof General, you must understand a little bit
of how X-Symbol works: read the documentation that is supplied with it.

The basic task is to set up a @i{token language} for your proof
assistant.  If your assistant is stored in the subdirectory
@var{myprover}, the token language will be called @var{myprover} and be
defined in a file @file{x-symbol-@var{myprover}.el} which is
automatically loaded by X-Symbol.  The name of the token language mode
will be @code{@var{myprover}sym}.

Proof General will check that the file @file{x-symbol-@var{myprover}.el}
exists and set up X-Symbol to load it.  The token language file must
define a number of standard settings, and X-Symbol will give warnings if
any of them are missing.

Apart from the token language file, there are several settings for
X-Symbol which you can set in the usual configuration file
@file{@var{myprover}.el}.  These settings are optional.

@c There's also proof-xsym-font-lock-keywords, but I don't 
@c really know what this setting is good for.

@c TEXI DOCSTRING MAGIC: proof-xsym-activate-command
@defvar proof-xsym-activate-command 
Command to activate token input/output for X-Symbol.@*
If non-nil, this command is sent to the proof assistant when 
X-Symbol support is activated.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-xsym-deactivate-command
@defvar proof-xsym-deactivate-command 
Command to deactivate token input/output for X-Symbol.@*
If non-nil, this command is sent to the proof assistant when 
X-Symbol support is deactivated.
@end defvar

We expect tokens to be used uniformly, so that along with each script
mode buffer, the response buffer and goals buffer also invoke X-Symbol
to display special characters in the same token language.  This happens
automatically.  If you want additional modes to use X-Symbol with the
token language for your proof assistant, you can set
@code{proof-xsym-extra-modes}.

@c TEXI DOCSTRING MAGIC: proof-xsym-extra-modes
@defvar proof-xsym-extra-modes 
List of additional mode names to use X-Symbol with Proof General tokens.@*
These modes will have X-Symbol enabled for the proof assistant token language,
in addition to the four modes for Proof General (script, shell, response, pbp).

Set this variable if you want additional modes to also display 
tokens (for example, editing documentation or source code files).
@end defvar



@node Writing more lisp code
@chapter Writing more lisp code

You may want to add some extra features to your instance of Proof
General which are not supported in the generic core.  To do this, you
can use the settings described above, plus a small number of fundamental
functions in Proof General which you can consider as exported in the
generic interface.  Be careful using more functions than are mentioned
here because the internals of Proof General may change between versions.

@menu
* Default values for generic settings::
* Adding prover-specific configurations::
* Useful variables::
* Useful functions and macros::        
@end menu

@node Default values for generic settings
@section Default values for generic settings

Several generic settings are defined using @code{defpgcustom} in
@file{proof-config.el}.  This introduces settings of the form
@code{<PA>-name} for each proof assistant @var{PA}.

To set the default value for these settings in prover-specific cases,
you should use the special @code{defpgdefault} macro:

@c TEXI DOCSTRING MAGIC: defpgdefault
@deffn Macro defpgdefault 
Set default for the proof assistant specific variable <PA>@var{-sym} to @var{value}.@*
This should be used in prover-specific code to alter the default values
for prover specific settings.

Usage: (defpgdefault SYM @var{value})
@end deffn

In your prover-specific code you can simply use the setting
@code{<PA>-sym} directly, i.e., write @code{myprover-home-page}.

In the generic code, you can use a macro, writing @code{(proof-ass
home-page)} to refer to the @code{<PA>-home-page} setting for the
currently running instance of Proof General.

@xref{Configuration variable mechanisms}, for more details on this
mechanism.


@node Adding prover-specific configurations
@section Adding prover-specific configurations

Apart from the generic settings, your prover instance will probably need
some specific customizable settings.

Defining new prover-specific settings using customize is pretty easy.
You should do it at least for your prover-specific user options.

The code in @file{proof-site.el} provides each prover with two
customization groups automatically (based on the name of the assistant): 
@code{<PA>} for user options for prover @var{PA}
and 
@code{<PA>-config} for configuration of prover @var{PA}.
Typically @code{<PA>-config} holds settings which are
constants but which may be nice to tweak.

The first group appears in the menu
@lisp
  ProofGeneral -> Customize -> <PA> 
@end lisp
The second group appears in the menu:
@lisp
  ProofGeneral -> Internals -> <PA> config
@end lisp

A typical use of @code{defcustom} looks like this:
@lisp
(defcustom myprover-search-page
  "http://findtheorem.myprover.org"
  "URL of search web page for myprover."
  :type 'string
  :group 'myprover-config)
@end lisp
This introduces a new customizable setting, which you might use to make
a menu entry, for example.  The default value is the string
@code{"http://findtheorem.myprover.org"}.






@node Useful variables
@section Useful variables

In @file{proof-compat}, two architecture flags are defined.  These can
be used to write conditional pieces of code for different Emacs and
operating systems.  


@c TEXI DOCSTRING MAGIC: proof-running-on-XEmacs

@defvar proof-running-on-XEmacs 
Non-nil if Proof General is running on XEmacs.
@end defvar
@c TEXI DOCSTRING MAGIC: proof-running-on-win32




@defvar proof-running-on-win32 
Non-nil if Proof General is running on a win32 system.
@end defvar
@node Useful functions and macros
@section Useful functions and macros

The recommended functions you may invoke are these:

@itemize @bullet
@item Any of the interactive commands (i.e. anything you
 can invoke with @kbd{M-x}, including all key-bindings)
@item Any of the internal functions and macros mentioned below
@end itemize

To insert text into the current (usually script) buffer, the function
@code{proof-insert} is useful.  There's also a handy macro
@code{proof-defshortcut} for defining shortcut functions using it.


@c TEXI DOCSTRING MAGIC: proof-insert
@defun proof-insert text
Insert @var{text} into the current buffer.@*
@var{text} may include these special characters:
@lisp
  %p  - place the point here after input
@end lisp
Any other %-prefixed character inserts itself.
@end defun

@c TEXI DOCSTRING MAGIC: proof-defshortcut
@deffn Macro proof-defshortcut 
Define shortcut function FN to insert @var{string}, optional keydef KEY.@*
This is intended for defining proof assistant specific functions.
@var{string} is inserted using @samp{@code{proof-insert}}, which see.
KEY is added onto @code{proof-assistant} map.
@end deffn
The function @code{proof-shell-invisible-command} is a useful utility
for sending a single command to the process.  You should use this to
implement user-level or internal functions rather than attempting to
directly manipulate the proof action list, or insert into the shell
buffer.

@c TEXI DOCSTRING MAGIC: proof-shell-invisible-command
@defun proof-shell-invisible-command cmd &optional wait
Send @var{cmd} to the proof process.  @*
Automatically add @code{proof-terminal-char} if necessary, examining
proof-shell-no-auto-terminate-commands.
By default, let the command be processed asynchronously.
But if optional @var{wait} command is non-nil, wait for processing to finish
before and after sending the command.
If @var{wait} is an integer, wait for that many seconds afterwards.
@end defun

There are several handy macros to help you define functions
which invoke @code{proof-shell-invisible-command}.

@c TEXI DOCSTRING MAGIC: proof-definvisible
@deffn Macro proof-definvisible 
Define function FN to send @var{string} to proof assistant, optional keydef KEY.@*
This is intended for defining proof assistant specific functions.
@var{string} is sent using @code{proof-shell-invisible-command}, which see.
KEY is added onto @code{proof-assistant} map.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-define-assistant-command
@deffn Macro proof-define-assistant-command 
Define command FN to send string @var{body} to proof assistant, based on @var{cmdvar}.@*
@var{body} defaults to @var{cmdvar}, a variable.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-define-assistant-command-witharg
@deffn Macro proof-define-assistant-command-witharg 
Define command FN to prompt for string @var{cmdvar} to proof assistant.@*
@var{cmdvar} is a function or string.  Automatically has history.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-format-filename






@defun proof-format-filename string filename
Format @var{string} by replacing quoted chars by escaped version of @var{filename}.

%e uses the canonicalized expanded version of filename (including
directory, using @code{default-directory} -- see @samp{@code{expand-file-name}}).

%r uses the unadjusted (possibly relative) version of @var{filename}.

%m ('module') uses the basename of the file, without directory
or extension.

%s means the same as %e.

Using %e can avoid problems with dumb proof assistants who don't
understand ~, for example.

For all these cases, the escapes in @samp{@code{proof-shell-filename-escapes}}
are processed.

If @var{string} is in fact a function, instead invoke it on @var{filename} and
return the resulting (string) value.
@end defun
@node Internals of Proof General
@chapter Internals of Proof General

This chapter sketches some of the internal functions and variables of
Proof General, to help developers who wish to understand or modify the
code.

Most of the documentation below is generated automatically from the
comments in the code.  Because Emacs lisp is interpreted and
self-documenting, the best way to find your way around the source is
inside Emacs once Proof General is loaded.  Read the source files, and
use functions such as @kbd{C-h v} and @kbd{C-h f}.

The code is split into files.  The following sections document the
important files, kept in the @file{generic/} subdirectory.

@menu
* Spans::                       
* Configuration variable mechanisms::
* Proof General site configuration::  
* Global variables::            
* Proof script mode::           
* Proof shell mode::            
* Debugging::
@end menu



@node Spans
@section Spans
@cindex spans
@cindex extents
@cindex overlays

@dfn{Spans} are an abstraction of XEmacs @dfn{extents} used to help
bridge the gulf between GNU Emacs and XEmacs.  In GNU Emacs, spans are
implemented using @dfn{overlays}.

See the files @file{span-extent.el} and @file{span-overlay.el} for the
implementation of the common interface in each case.

@node Proof General site configuration
@section Proof General site configuration
@cindex installation directories
@cindex site configuration

The file @file{proof-site.el} contains the initial configuration for
Proof General for the site (or user) and the choice of provers.

The first part of the configuration is to set
@code{proof-home-directory} to the directory that @file{proof-site.el}
is located in, or to the variable of the environment variable
@code{PROOFGENERAL_HOME} if that is set.

@c TEXI DOCSTRING MAGIC: proof-home-directory
@defvar proof-home-directory 
Directory where Proof General is installed. Ends with slash.@*
Default value taken from environment variable @samp{PROOFGENERAL_HOME} if set, 
otherwise based on where the file @samp{proof-site.el} was loaded from.
You can use customize to set this variable.
@end defvar

@c They're no longer options.
@c The default value for @code{proof-home-directory} mentioned above is the
@c one for the author's system, it won't be the same for you!

Further directory variables allow the files of Proof General to be split
up and installed across a system if need be, rather than under the
@code{proof-home-directory} root.

@c TEXI DOCSTRING MAGIC: proof-images-directory
@defvar proof-images-directory 
Where Proof General image files are installed. Ends with slash.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-info-directory
@defvar proof-info-directory 
Where Proof General Info files are installed. Ends with slash.
@end defvar



@cindex mode stub
After defining these settings, we define a @dfn{mode stub} for each
proof assistant enabled.  The mode stub will autoload Proof General for
the right proof assistant when a file is visited with the corresponding
extension.  The proof assistants enabled are the ones listed
in the @code{proof-assistants} setting.

@c TEXI DOCSTRING MAGIC: proof-assistants
@defopt proof-assistants 
Choice of proof assistants to use with Proof General.@*
A list of symbols chosen from: @code{'demoisa} @code{'isar} @code{'isa} @code{'lego} @code{'coq} @code{'phox} @code{'hol98} @code{'acl2} @code{'plastic} @code{'twelf}.
Each proof assistant defines its own instance of Proof General,
providing session control, script management, etc.  Proof General
will be started automatically for the assistants chosen here.
To avoid accidently invoking a proof assistant you don't have,
only select the proof assistants you (or your site) may need.

You can select which proof assistants you want by setting this
variable before @samp{proof-site.el} is loaded, or by setting
the environment variable @samp{PROOFGENERAL_ASSISTANTS} to the
symbols you want, for example "lego isa".  Or you can
edit the file @samp{proof-site.el} itself.

Note: to change proof assistant, you must start a new Emacs session.

The default value is @code{nil}.
@end defopt

The file @file{proof-site.el} also defines a version variable.

@c TEXI DOCSTRING MAGIC: proof-general-version
@defvar proof-general-version 
Version string identifying Proof General release.
@end defvar



@node Configuration variable mechanisms
@section Configuration variable mechanisms
@cindex conventions
@cindex user options
@cindex configuration
@cindex settings

The file @file{proof-config.el} defines the configuration variables for
Proof General, including instantiation parameters and user options.  See
previous chapters for details of its contents.  Here we mention some
conventions for declaring user options.

Global user options and instantiation parameters are declared using
@code{defcustom} as usual.  User options should have `@code{*}' as the
first character of their docstrings (standard Emacs convention) and live
in the customize group @code{proof-user-options}.  See
@file{proof-config.el} for the groups for instantiation parameters.

User options which are generic (having separate instances for each
prover) and instantiation parameters (by definition generic) can be
declared using the special macro @code{defpgcustom}.  It is used in the
same way as @code{defcustom}, except that the symbol declared will
automatically be prefixed by the current proof assistant symbol.

@c TEXI DOCSTRING MAGIC: defpgcustom
@deffn Macro defpgcustom 
Define a new customization variable <PA>@var{-sym} for the current proof assistant.@*
The function proof-assistant-<SYM> is also defined, which can be used in the 
generic portion of Proof General to set and retrieve the value for the current p.a.
Arguments as for @samp{defcustom}, which see.

Usage: (defpgcustom SYM &rest @var{args}).
@end deffn

In specific instances of Proof General, the macro @code{defpgdefault}
can be used to give a default value for a generic setting.

@c TEXI DOCSTRING MAGIC: defpgdefault
@deffn Macro defpgdefault 
Set default for the proof assistant specific variable <PA>@var{-sym} to @var{value}.@*
This should be used in prover-specific code to alter the default values
for prover specific settings.

Usage: (defpgdefault SYM @var{value})
@end deffn

All new instantiation variables are best declared using the
@code{defpgcustom} mechanism (old code may be converted gradually).
Customizations which are liable to be different for different instances
of Proof General are also best declared in this way.  An example is the
use of X Symbol, controlled by @code{@emph{PA}-x-symbol-enable}, since
it works poorly or not at all with some provers.

To access the generic settings, the following four functions and
macros are useful.

@c TEXI DOCSTRING MAGIC: proof-ass
@deffn Macro proof-ass 
Return the value for SYM for the current prover.
@end deffn
@c TEXI DOCSTRING MAGIC: proof-ass-sym
@deffn Macro proof-ass-sym 
Return the symbol for SYM for the current prover.  SYM not evaluated.
@end deffn
@c TEXI DOCSTRING MAGIC: proof-ass-symv
@defun proof-ass-symv sym
Return the symbol for @var{sym} for the current prover.  @var{sym} is evaluated.
@end defun

If changing a user option setting amounts to more than just setting a
variable (it may have some dynamic effect), we can set the
@code{custom-set} property for the variable to the function
@code{proof-set-value} which does an ordinary @code{set-default} to set
the variable, and then calls a function with the same name as the
variable, to do whatever is necessary according to the new value for the
variable.  

There are several settings which can be switched on or off by the user,
which use this @code{proof-set-value} mechanism.  They are controlled by
boolean variables with names like @code{proof-@var{foo}-enable}, and
appear at the start of the customize group @code{proof-user-options}.
They should be edited by the user through the customization mechanism,
and set in the code using @code{customize-set-variable}.

In @code{proof-utils.el} there is a handy macro,
@code{proof-deftoggle}, which constructs an interactive function
for toggling boolean customize settings.  We can use this to make an
interactive function @code{proof-@var{foo}-toggle} to put on a menu or
bind to a key, for example.

This general scheme is followed as far as possible, to give uniform
behaviour and appearance for boolean user options, as well as
interfacing properly with the @code{customize} mechanism.

@c TEXI DOCSTRING MAGIC: proof-set-value
@defun proof-set-value sym value
Set a customize variable using @code{set-default} and a function.@*
We first call @samp{@code{set-default}} to set @var{sym} to @var{value}.
Then if there is a function @var{sym} (i.e. with the same name as the
variable @var{sym}), it is called to take some dynamic action for the new
setting.  

If there is no function @var{sym}, we try stripping 
@code{proof-assistant-symbol} and adding "proof-" instead to get
a function name.  This extends @code{proof-set-value} to work with
generic individual settings.

The dynamic action call only happens when values @strong{change}: as an
approximation we test whether proof-config is fully-loaded yet.
@end defun

@c TEXI DOCSTRING MAGIC: proof-deftoggle
@deffn Macro proof-deftoggle 
Define a function VAR-toggle for toggling a boolean customize setting VAR.@*
The toggle function uses @code{customize-set-variable} to change the variable.
@var{othername} gives an alternative name than the default <VAR>-toggle.
The name of the defined function is returned.
@end deffn
@node Global variables
@section Global variables

Global variables are defined in @file{proof.el}.  The same file defines
a few utility functions and some triggers to load in the other files.

@c TEXI DOCSTRING MAGIC: proof-script-buffer
@defvar proof-script-buffer 
The currently active scripting buffer or nil if none.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-buffer
@defvar proof-shell-buffer 
Process buffer where the proof assistant is run.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-response-buffer
@defvar proof-response-buffer 
The response buffer.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-goals-buffer
@defvar proof-goals-buffer 
The goals buffer.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-buffer-type
@defvar proof-buffer-type 
Symbol indicating the type of this buffer: @code{'script}, @code{'shell}, @code{'pbp}, or @code{'response}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-included-files-list
@defvar proof-included-files-list 
List of files currently included in proof process.@*
This list contains files in canonical truename format
(see @samp{@code{file-truename}}).

Whenever a new file is being processed, it gets added to this list
via the @code{proof-shell-process-file} configuration settings.
When the prover retracts a file, this list is resynchronised via the
@code{proof-shell-retract-files-regexp} and @code{proof-shell-compute-new-files-list} 
configuration settings.

Only files which have been @strong{fully} processed should be included here.
Proof General itself will automatically add the filenames of a script
buffer which has been completely read when scripting is deactivated.
It will automatically remove the filename of a script buffer which
is completely unread when scripting is deactivated.

NB: Currently there is no generic provision for removing files which
are only partly read-in due to an error, so ideally the proof assistant
should only output a processed message when a file has been successfully
read.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-proof-completed
@defvar proof-shell-proof-completed 
Flag indicating that a completed proof has just been observed.@*
If non-nil, the value counts the commands from the last command
of the proof (starting from 1).
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-error-or-interrupt-seen
@defvar proof-shell-error-or-interrupt-seen 
Flag indicating that an error or interrupt has just occurred.@*
Set to @code{'error} or @code{'interrupt} if one was observed from the proof 
assistant during the last group of commands.
@end defvar


@node Proof script mode
@section Proof script mode

The file @file{proof-script.el} contains the main code for proof script
mode, as well as definitions of menus, key-bindings, and user-level
functions.

Proof scripts have two important variables for the locked and queue
regions.  These variables are local to each script buffer (although we
only really need one queue span in total rather than one per buffer).

@c TEXI DOCSTRING MAGIC: proof-locked-span
@defvar proof-locked-span 
The locked span of the buffer.@*
Each script buffer has its own locked span, which may be detached
from the buffer.
Proof General allows buffers in other modes also to be locked;
these also have a non-nil value for this variable.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-queue-span
@defvar proof-queue-span 
The queue span of the buffer.  May be detached if inactive or empty.
@end defvar

Various utility functions manipulate and examine the spans.  An
important one is @code{proof-init-segmentation}.

@c TEXI DOCSTRING MAGIC: proof-init-segmentation
@defun proof-init-segmentation 
Initialise the queue and locked spans in a proof script buffer.@*
Allocate spans if need be.  The spans are detached from the
buffer, so the regions are made empty by this function.
Also clear list of script portions.
@end defun

For locking files loaded by a proof assistant, we use the next function.

@c TEXI DOCSTRING MAGIC: proof-complete-buffer-atomic
@defun proof-complete-buffer-atomic buffer
Make sure @var{buffer} is marked as completely processed, completing with a single step.

If buffer already contains a locked region, only the remainder of the
buffer is closed off atomically.

This works for buffers which are not in proof scripting mode too,
to allow other files loaded by proof assistants to be marked read-only.
@end defun

Atomic locking is instigated by the next function, which uses the
variables @code{proof-included-files-list} documented earlier
(@pxref{Handling multiple files} and @pxref{Global variables}).

@c TEXI DOCSTRING MAGIC: proof-register-possibly-new-processed-file
@defun proof-register-possibly-new-processed-file file &optional informprover noquestions
Register a possibly new @var{file} as having been processed by the prover.

If @var{informprover} is non-nil, the proof assistant will be told about this,
to co-ordinate with its internal file-management.  (Otherwise we assume
that it is a message from the proof assistant which triggers this call).
In this case, the user will be queried to save some buffers, unless
@var{noquestions} is non-nil.

No action is taken if the file is already registered.

A warning message is issued if the register request came from the
proof assistant and Emacs has a modified buffer visiting the file.
@end defun

An important pair of functions activate and deactivate scripting for the
current buffer.  A change in the state of active scripting can trigger
various actions, such as starting up the proof assistant, or altering
@code{proof-included-files-list}.

@c TEXI DOCSTRING MAGIC: proof-activate-scripting
@deffn Command proof-activate-scripting &optional nosaves queuemode
Ready prover and activate scripting for the current script buffer.

The current buffer is prepared for scripting. No changes are
necessary if it is already in Scripting minor mode. Otherwise, it
will become the new active scripting buffer, provided scripting
can be switched off in the previous active scripting buffer
with @samp{@code{proof-deactivate-scripting}}.

Activating a new script buffer may be a good time to ask if the 
user wants to save some buffers; this is done if the user
option @samp{@code{proof-query-file-save-when-activating-scripting}} is set
and provided the optional argument @var{nosaves} is non-nil.

The optional argument @var{queuemode} relaxes the test for a
busy proof shell to allow one which has mode @var{queuemode}.
In all other cases, a proof shell busy error is given.

Finally, the hooks @samp{@code{proof-activate-scripting-hook}} are run.  
This can be a useful place to configure the proof assistant for
scripting in a particular file, for example, loading the
correct theory, or whatever.  If the hooks issue commands
to the proof assistant (via @samp{@code{proof-shell-invisible-command}})
which result in an error, the activation is considered to
have failed and an error is given.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-deactivate-scripting
@deffn Command proof-deactivate-scripting &optional forcedaction
Deactivate scripting for the active scripting buffer.

Set @code{proof-script-buffer} to nil and turn off the modeline indicator.
No action if there is no active scripting buffer.  

We make sure that the active scripting buffer either has no locked
region or a full locked region (everything in it has been processed).
If this is not already the case, we question the user whether to
retract or assert, or automatically take the action indicated in the
user option @samp{@code{proof-auto-action-when-deactivating-scripting}.}

If the scripting buffer is (or has become) fully processed, and it is
associated with a file, it is registered on
@samp{@code{proof-included-files-list}}.  Conversely, if it is (or has become)
empty, we make sure that it is @strong{not} registered.  This is to be
certain that the included files list behaves as we might expect with
respect to the active scripting buffer, in an attempt to harmonize
mixed scripting and file reading in the prover.

This function either succeeds, fails because the user refused to
process or retract a partly finished buffer, or gives an error message
because retraction or processing failed.  If this function succeeds,
then @code{proof-script-buffer} is nil afterwards.

The optional argument @var{forcedaction} overrides the user option
@samp{@code{proof-auto-action-when-deactivating-scripting}} and prevents
questioning the user.  It is used to make a value for
the @code{kill-buffer-hook} for scripting buffers, so that when
a scripting buffer is killed it is always retracted.
@end deffn

The function @code{proof-segment-up-to} is the main one used for parsing
the proof script buffer.  There are several variants of this function
available corresponding to different parsing strategies; the appropriate
one is aliased to @code{proof-segment-up-to} according to which
configuration variables have been set.  If only
@code{proof-script-command-end-regexp} or @code{proof-terminal-char} are set,
then the default is @code{proof-segment-up-to-cmdend}.  If
@code{proof-script-command-start-regexp} is set, the choice is
@code{proof-segment-up-to-cmdstart}.  

@c TEXI DOCSTRING MAGIC: proof-segment-up-to-cmdend
@defun proof-segment-up-to-cmdend pos &optional next-command-end
Parse the script buffer from end of locked to @var{pos}.@*
Return a list of (type, string, int) tuples.

Each tuple denotes the command and the position of its terminator,
type is one of @code{'comment}, or @code{'cmd}. @code{'unclosed-comment} may be consed onto
the start if the segment finishes with an unclosed comment.

If optional @var{next-command-end} is non-nil, we include the command
which continues past @var{pos}, if any.

This version is used when @samp{@code{proof-script-command-end-regexp}} is set.
@end defun

@c TEXI DOCSTRING MAGIC: proof-segment-up-to-cmdstart
@defun proof-segment-up-to-cmdstart pos &optional next-command-end
Parse the script buffer from end of locked to @var{pos}.@*
Return a list of (type, string, int) tuples.

Each tuple denotes the command and the position of its terminator,
type is one of @code{'comment}, or @code{'cmd}.

If optional @var{next-command-end} is non-nil, we include the command
which continues past @var{pos}, if any.  (NOT @var{implemented} IN @var{this} @var{version}).

This version is used when @samp{@code{proof-script-command-start-regexp}} is set.
@end defun


The function @code{proof-semis-to-vanillas} is used to convert
a parsed region of the script into a series of commands to
be sent to the proof assistant.

@c TEXI DOCSTRING MAGIC: proof-semis-to-vanillas
@defun proof-semis-to-vanillas semis &optional callback-fn
Convert a sequence of terminator positions to a set of vanilla extents.@*
Proof terminator positions @var{semis} has the form returned by
the function proof-segment-up-to.
Set the callback to @var{callback-fn} or @code{'proof-done-advancing} by default.
@end defun

The function @code{proof-assert-until-point} is the main one used to
process commands in the script buffer.  It's actually used to implement
the assert-until-point, electric terminator keypress, and
find-next-terminator behaviours.  In different cases we want different
things, but usually the information (i.e. are we inside a comment) isn't
available until we've actually run @code{proof-segment-up-to (point)},
hence all the different options when we've done so.

@c TEXI DOCSTRING MAGIC: proof-assert-until-point
@defun proof-assert-until-point &optional unclosed-comment-fun ignore-proof-process-p
Process the region from the end of the locked-region until point.@*
Default action if inside a comment is just process as far as the start of
the comment. 

If you want something different, put it inside
@var{unclosed-comment-fun}. If @var{ignore-proof-process-p} is set, no commands
will be added to the queue and the buffer will not be activated for
scripting.
@end defun

@code{proof-assert-next-command} is a variant of this function.

@c TEXI DOCSTRING MAGIC: proof-assert-next-command
@deffn Command proof-assert-next-command &optional unclosed-comment-fun ignore-proof-process-p dont-move-forward for-new-command
Process until the end of the next unprocessed command after point.@*
If inside a comment, just process until the start of the comment.  

If you want something different, put it inside @var{unclosed-comment-fun}. 
If @var{ignore-proof-process-p} is set, no commands will be added to the queue.
Afterwards, move forward to near the next command afterwards, unless
@var{dont-move-forward} is non-nil.  If @var{for-new-command} is non-nil,
a space or newline will be inserted automatically.
@end deffn

The main command for retracting parts of a script is
@code{proof-retract-until-point}.

@c TEXI DOCSTRING MAGIC: proof-retract-until-point
@defun proof-retract-until-point &optional delete-region
Set up the proof process for retracting until point.@*
In particular, set a flag for the filter process to call 
@samp{@code{proof-done-retracting}} after the proof process has successfully 
reset its state.
If @var{delete-region} is non-nil, delete the region in the proof script
corresponding to the proof command sequence.
If invoked outside a locked region, undo the last successfully processed
command.
@end defun

To clean up when scripting is stopped, a script buffer is killed, or the
proof assistant exits, we use the functions
@code{proof-restart-buffers} and
@code{proof-script-remove-all-spans-and-deactivate}.

@c TEXI DOCSTRING MAGIC: proof-restart-buffers
@defun proof-restart-buffers buffers
Remove all extents in @var{buffers} and maybe reset @samp{@code{proof-script-buffer}}.@*
No effect on a buffer which is nil or killed.  If one of the buffers
is the current scripting buffer, then @code{proof-script-buffer} 
will deactivated.
@end defun

@c TEXI DOCSTRING MAGIC: proof-script-remove-all-spans-and-deactivate
@defun proof-script-remove-all-spans-and-deactivate 
Remove all spans from scripting buffers via @code{proof-restart-buffers}.
@end defun


@c
@c SECTION: Proof Shell Mode
@c
@node Proof shell mode
@section Proof shell mode
@cindex proof shell mode
@cindex comint-mode

The proof shell mode code is in the file @file{proof-shell.el}.  Proof
shell mode is defined to inherit from @code{comint-mode} using
@code{define-derived-mode} near the end of the file.  The bulk of the
code in the file is concerned with sending code to and from the shell,
and processing output for the associated buffers (goals and response).

Good process handling is a tricky issue.  Proof General attempts to
manage the process strictly, by maintaining a queue of commands to send
to the process.  Once a command has been processed, another one is
popped off the queue and sent.

There are several important internal variables which control
interaction with the process.

@c TEXI DOCSTRING MAGIC: proof-shell-busy
@defvar proof-shell-busy 
A lock indicating that the proof shell is processing.@*
When this is non-nil, @code{proof-shell-ready-prover} will give
an error.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-marker
@defvar proof-marker 
Marker in proof shell buffer pointing to previous command input.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-action-list
@defvar proof-action-list 
A list of@*
@lisp
  (@var{span} @var{command} @var{action})
@end lisp
triples, which is a queue of things to do.
See the functions @samp{@code{proof-start-queue}} and @samp{proof-exec-loop}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-analyse-using-stack
@defvar proof-analyse-using-stack 
Choice of syntax tree encoding for terms.

If nil, prover is expected to make no optimisations.
If non-nil, the pretty printer of the prover only reports local changes. 
For @var{lego} 1.3.1 use @samp{nil}, for Coq 6.2, use @samp{t}.
@end defvar


The function @code{proof-shell-start} is used to initialise a shell
buffer and the associated buffers.  

@c TEXI DOCSTRING MAGIC: proof-shell-start
@deffn Command proof-shell-start 
Initialise a shell-like buffer for a proof assistant.

Also generates goal and response buffers.
Does nothing if proof assistant is already running.
@end deffn

The function @code{proof-shell-kill-function} performs the converse
function of shutting things down; it is used as a hook function for
@code{kill-buffer-hook}.  Then no harm occurs if the user kills the
shell directly, or if it is done more cautiously via
@code{proof-shell-exit}.  The function @code{proof-shell-restart} allows
a less drastic way of restarting scripting, other than killing and
restarting the process.

@c TEXI DOCSTRING MAGIC: proof-shell-kill-function
@defun proof-shell-kill-function 
Function run when a proof-shell buffer is killed.@*
Attempt to shut down the proof process nicely and
clear up all the locked regions and state variables.
Value for @code{kill-buffer-hook} in shell buffer.
Also called by @code{proof-shell-bail-out} if the process is
exited by hand (or exits by itself).
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-exit
@deffn Command proof-shell-exit 
Query the user and exit the proof process.

This simply kills the @code{proof-shell-buffer} relying on the hook function
@code{proof-shell-kill-function} to do the hard work.
@end deffn

@c TEXI DOCSTRING MAGIC: proof-shell-bail-out
@defun proof-shell-bail-out process event
Value for the process sentinel for the proof assistant process.@*
If the proof assistant dies, run @code{proof-shell-kill-function} to
cleanup and remove the associated buffers.  The shell buffer is
left around so the user may discover what killed the process.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-restart
@deffn Command proof-shell-restart 
Clear script buffers and send @code{proof-shell-restart-cmd}.@*
All locked regions are cleared and the active scripting buffer
deactivated.  

If the proof shell is busy, an interrupt is sent with
@code{proof-interrupt-process} and we wait until the process is ready.

The restart command should re-synchronize Proof General with the proof
assistant, without actually exiting and restarting the proof assistant
process.

It is up to the proof assistant how much context is cleared: for
example, theories already loaded may be "cached" in some way,
so that loading them the next time round only performs a re-linking
operation, not full re-processing.  (One way of caching is via
object files, used by Lego and Coq).
@end deffn

@c
@c INPUT
@c
@subsection Input to the shell

Input to the proof shell via the queue region is managed by the
functions @code{proof-start-queue} and @code{proof-shell-exec-loop}.

@c TEXI DOCSTRING MAGIC: proof-start-queue
@defun proof-start-queue start end alist
Begin processing a queue of commands in @var{alist}.@*
If @var{start} is non-nil, @var{start} and @var{end} are buffer positions in the
active scripting buffer for the queue region.

This function calls @samp{@code{proof-append-alist}}.
@end defun

@c TEXI DOCSTRING MAGIC: proof-append-alist

@defun proof-append-alist alist &optional queuemode
Chop off the vacuous prefix of the command queue @var{alist} and queue it.@*
For each @samp{@code{proof-no-command}} item at the head of the list, invoke its 
callback and remove it from the list.

Append the result onto @samp{@code{proof-action-list}}, and if the proof 
shell isn't already busy, grab the lock with @var{queuemode} and
start processing the queue.

If the proof shell is busy when this function is called,
then @var{queuemode} must match the mode of the queue currently
being processed.
@end defun
@vindex proof-action-list
@c TEXI DOCSTRING MAGIC: proof-shell-exec-loop
@defun proof-shell-exec-loop 
Process the @code{proof-action-list}.

@samp{@code{proof-action-list}} contains a list of (@var{span} @var{command} @var{action}) triples.

If this function is called with a non-empty @code{proof-action-list}, the
head of the list is the previously executed command which succeeded.
We execute (@var{action} @var{span}) on the first item, then (@var{action} @var{span}) on any
following items which have @code{proof-no-command} as their cmd components.
If a there is a next command after that, send it to the process.  If
the action list becomes empty, unlock the process and remove the queue
region.

The return value is non-nil if the action list is now empty.
@end defun

Input is actually inserted into the shell buffer and sent to the process
by the low-level function @code{proof-shell-insert}.  

@c TEXI DOCSTRING MAGIC: proof-shell-insert
@defun proof-shell-insert string action
Insert @var{string} at the end of the proof shell, call @code{comint-send-input}.

First call @code{proof-shell-insert-hook}.  The argument @var{action} may be
examined by the hook to determine how to process the @var{string} variable.

Then strip @var{string} of carriage returns before inserting it and updating
@code{proof-marker} to point to the end of the newly inserted text.

Do not use this function directly, or output will be lost.  It is only
used in @code{proof-append-alist} when we start processing a queue, and in
@code{proof-shell-exec-loop}, to process the next item.
@end defun


When Proof General is processing a queue of commands, the lock
is managed using a couple of utility functions.  You should
not need to use these directly.


@c TEXI DOCSTRING MAGIC: proof-grab-lock

@defun proof-grab-lock &optional queuemode
Grab the proof shell lock, starting the proof assistant if need be.@*
Runs @code{proof-state-change-hook} to notify state change.
Clears the @code{proof-shell-error-or-interrupt-seen} flag.
If @var{queuemode} is supplied, set the lock to that value.
@end defun
@c TEXI DOCSTRING MAGIC: proof-release-lock







@defun proof-release-lock &optional err-or-int
Release the proof shell lock, with error or interrupt flag @var{err-or-int}.@*
Clear @code{proof-shell-busy}, and set @code{proof-shell-error-or-interrupt-seen}
to err-or-int.
@end defun


@c
@c OUTPUT
@c
@subsection Output from the shell

Two main functions deal with output, @code{proof-shell-process-output}
and @code{proof-shell-process-urgent-message}.  In effect we consider
the output to be two streams intermingled: the "urgent" messages which
have "eager" annotations, as well as the ordinary ruminations from the
prover.  

The idea is to conceal as much irrelevant information from the user as
possible; only the remaining output between prompts and after the last
urgent message will be a candidate for the goal or response buffer.  The
internal variable @code{proof-shell-urgent-message-marker} tracks the
last urgent message seen.

When output is grabbed from the prover process, it is stored into
@code{proof-shell-last-output}, and its type is stored in
@code{proof-shell-last-output-kind}.  Output which is deferred 
or possibly discarded until the queue is empty is copied into
@code{proof-shell-delayed-output}, with type
@code{proof-shell-delayed-output-kind}.


@c TEXI DOCSTRING MAGIC: proof-shell-last-output
@defvar proof-shell-last-output 
A record of the last string seen from the proof system.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-last-output-kind
@defvar proof-shell-last-output-kind 
A symbol denoting the type of the last output string from the proof system.@*
Specifically:
@lisp
 @code{'interrupt}      An interrupt message
 @code{'error}          An error message
 @code{'abort}          A proof abort message
 @code{'loopback}       A command sent from the PA to be inserted into the script
 @code{'response}       A response message
 @code{'goals}          A goals (proof state) display
 @code{'systemspecific} Something specific to a particular system,
                  -- see @samp{@code{proof-shell-process-output-system-specific}}
@end lisp
The output corresponding to this will be in @code{proof-shell-last-output}.

See also @samp{@code{proof-shell-proof-completed}} for further information about
the proof process output, when ends of proofs are spotted.

This variable can be used for instance specific functions which want
to examine @code{proof-shell-last-output}.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-delayed-output
@defvar proof-shell-delayed-output 
A copy of @code{proof-shell-last-output} held back for processing at end of queue.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-delayed-output-kind
@defvar proof-shell-delayed-output-kind 
A copy of proof-shell-last-output-lind held back for processing at end of queue.
@end defvar
@vindex proof-action-list

@c TEXI DOCSTRING MAGIC: proof-shell-process-output
@defun proof-shell-process-output cmd string
Process shell output (resulting from @var{cmd}) by matching on @var{string}.@*
@var{cmd} is the first part of the @code{proof-action-list} that lead to this
output.  The result of this function is a pair (@var{symbol} @var{newstring}).

Here is where we recognizes interrupts, abortions of proofs, errors,
completions of proofs, and proof step hints (proof by pointing results).
They are checked for in this order, using
@lisp
  @code{proof-shell-interrupt-regexp}
  @code{proof-shell-error-regexp}
  @code{proof-shell-abort-goal-regexp}
  @code{proof-shell-proof-completed-regexp}
  @code{proof-shell-result-start}
@end lisp
All other output from the proof engine will be reported to the user in
the response buffer by setting @code{proof-shell-delayed-output} to a cons
cell of ('insert . @var{text}) where @var{text} is the text string to be inserted.

Order of testing is: interrupt, abort, error, completion.

To extend this function, set @code{proof-shell-process-output-system-specific}.

The "aborted" case is intended for killing off an open proof during
retraction.  Typically it matches the message caused by a
@code{proof-kill-goal-command}.  It simply inserts the word "Aborted" into
the response buffer.  So it is expected to be the result of a 
retraction, rather than the indication that one should be made.

This function sets @samp{@code{proof-shell-last-output}} and @samp{@code{proof-shell-last-output-kind}},
which see.
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-urgent-message-marker
@defvar proof-shell-urgent-message-marker 
Marker in proof shell buffer pointing to end of last urgent message.
@end defvar

@c TEXI DOCSTRING MAGIC: proof-shell-process-urgent-message
@defun proof-shell-process-urgent-message message
Analyse urgent @var{message} for various cases.@*
Cases are: included file, retracted file, cleared response buffer, 
variable setting or dependency list. 
If none of these apply, display @var{message}.

@var{message} should be a string annotated with 
@code{proof-shell-eager-annotation-start}, @code{proof-shell-eager-annotation-end}.
@end defun

The main processing point which triggers other actions is
@code{proof-shell-filter}.

@c TEXI DOCSTRING MAGIC: proof-shell-filter
@defun proof-shell-filter str
Filter for the proof assistant shell-process.@*
A function for @code{comint-output-filter-functions}.

Deal with output and issue new input from the queue.

Handle urgent messages first.  As many as possible are processed,
using the function @samp{@code{proof-shell-process-urgent-messages}}.

Otherwise wait until an annotated prompt appears in the input.  
If @code{proof-shell-wakeup-char} is set, wait until we see that in the
output chunk @var{str}.  This optimizes the filter a little bit.

If a prompt is seen, run @code{proof-shell-process-output} on the output
between the new prompt and the last input (position of @code{proof-marker})
or the last urgent message (position of
@code{proof-shell-urgent-message-marker}), whichever is later.  
For example, in this case:
@lisp
 PROMPT> @var{input}
 @var{output-1}
 @var{urgent-message}
 @var{output-2}
 PROMPT>
@end lisp
@code{proof-marker} is set after @var{input} by @code{proof-shell-insert} and
@code{proof-shell-urgent-message-marker} is set after @var{urgent-message}.
Only @var{output-2} will be processed.  For this reason, error
messages and interrupt messages should @strong{not} be considered
urgent messages.

Output is processed using the function
@samp{@code{proof-shell-filter-process-output}}.

The first time that a prompt is seen, @code{proof-marker} is 
initialised to the end of the prompt.  This should
correspond with initializing the process.  The 
ordinary output before the first prompt is ignored (urgent messages, 
however, are always processed; hence their name).
@end defun

@c TEXI DOCSTRING MAGIC: proof-shell-filter-process-output
@defun proof-shell-filter-process-output string
Subroutine of @code{proof-shell-filter} to process output @var{string}.

Appropriate action is taken depending on the what
@code{proof-shell-process-output} returns: maybe handle an interrupt, an
error, or deal with ordinary output which is a candidate for the goal
or response buffer.  Ordinary output is only displayed when the proof
action list becomes empty, to avoid a confusing rapidly changing
output.

After processing the current output, the last step undertaken
by the filter is to send the next command from the queue.
@end defun






@c
@c SECTION: Debugging
@c
@node Debugging
@section Debugging
@cindex debugging

@c FIXME: better to have general hints on Elisp earlier, plus some
@c links to helpful docs.

To debug Proof General, it may be helpful to set the
configuration variable @code{proof-show-debug-messages}.

@c TEXI DOCSTRING MAGIC: proof-show-debug-messages
@defopt proof-show-debug-messages 
Whether to display debugging messages in the response buffer.@*
If non-nil, debugging messages are displayed in the response giving
information about what Proof General is doing.
To avoid erasing the messages shortly after they're printed, 
you should set @samp{@code{proof-tidy-response}} to nil.

The default value is @code{nil}.
@end defopt

For more information about debugging Emacs lisp, consult the Emacs Lisp
Reference Manual.  I recommend using the source-level debugger
@code{edebug}.














@c
@c
@c APPENDIX: Plans and ideas
@c
@c
@node Plans and ideas
@appendix Plans and ideas

This appendix contains some tentative plans and ideas for improving
Proof General.

This appendix is no longer extended: instead we keep a list of Proof
General projects on the web, and forthcoming plans and ideas in the
@file{TODO} and @file{todo} files included in the ordinary and
developers PG distributions, respectively.  Once the items mentioned
below are implemented, they will be removed from here.

Please send us contributions to our wish lists, or better still, an
offer to implement something from them!

@menu
* Proof by pointing and similar features::
* Granularity of atomic command sequences::  
* Browser mode for script files and theories::  
@end menu

@node Proof by pointing and similar features
@section Proof by pointing and similar features
@cindex proof by pointing

This is a note by David Aspinall about proof by pointing and similar
features.

Proof General already supports proof by pointing, and experimental
support is provided in LEGO.  We would like to extend this support to
other proof assistants.  Unfortunately, proof by pointing requires
rather heavy support from the proof assistant.  There are two aspects to
the support:
@itemize @bullet
@item term structure mark-up
@item proof by pointing command generation
@end itemize
Term structure mark-up is useful in itself: it allows the user to
explore the structure of a term using the mouse (the smallest
subexpression that the mouse is over is highlighted), and easily copy
subterms from the output to a proof script.

Command generation for proof by pointing is usually specific to a
particular logic in use, if we hope to generate a good proof command
unambiguously for any particular click. However, Proof General could
easily be generalised to offer the user a context-sensitive choice of
next commands to apply, which may be more useful in practice, and a
worthy addition to Proof General.

Implementors of new proof assistants should be encouraged to consider
supporting term-structure mark up from the start.  Command generation
should be something that the logic-implementor can specify in some way.

Of the supported provers, we can certainly hope for proof-by-pointing
support from Coq, since the CtCoq proof-by-pointing code has been moved
into the Coq kernel lately.  I hope the Coq community can encourage
somebody to do this.


@node Granularity of atomic command sequences
@section Granularity of atomic command sequences
@c @cindex Granularity of Atomic Sequences
@c @cindex Retraction
@c @cindex Goal
@cindex ACS (Atomic Command Sequence)

This is a proposal by Thomas Kleymann for generalising the way Proof
General handles sequences of proof commands (see @i{Goal-save
sequences} in the user manual), particularly to make retraction more flexible.

The blue region of a script buffer contains the initial segment of
the proof script which has been processed successfully. It consists of
atomic sequences of commands (ACS). Retraction is supported to the
beginning of every ACS. By default, every command is an ACS. But the
granularity of atomicity should be able to be adjusted.

This is essential when arbitrary retraction is not supported. Usually,
after a theorem has been proved, one may only retract to the start of
the goal. One needs to mark the proof of the theorem as an ACS. At
present, support for goal-save sequences (see @i{Goal-save sequences} in
the user manual), has been hard wired. No other ACS are currently
supported. We propose the following to overcome this deficiency:

@vtable @code
@item proof-atomic-sequents-list
is a list of instructions for setting up ACSs. Each instruction is a
list of the form @code{(@var{end} @var{start} &optional
@var{forget-command})}. @var{end} is a regular expression to recognise
the last command in an ACS. @var{start} is a function. Its input is the
last command of an ACS. Its output is a regular expression to recognise
the first command of the ACS. It is evaluated once and, starting with the
command matched by @var{end}, the output is
successively matched against previously processed commands until a match
occurs (or the beginning of the current buffer is reached). The region
determined by (@var{start},@var{end}) is locked as an ACS. Optionally,
the ACS is annotated with the actual command to retract the ACS. This is 
computed by applying @var{forget-command} to the first and last command
of the ACS.

For convenience one might also want to allow @var{start} to be the
symbol @samp{t} as a convenient short-hand for @code{'(lambda (str)
".")} which always matches.
@end vtable

@node Browser mode for script files and theories
@section Browser mode for script files and theories

This is a proposal by David Aspinall for a browser window.

A browser window should provide support for browsing script files and
theories.  We should be able to inspect data in varying levels of
detail, perhaps using outlining mechanisms.  For theories, it would be
nice to query the running proof assistant.  This may require support
from the assistant in the form of output which has been specially
marked-up with an SGML like syntax, for example.

A browser would be useful to:
@itemize @bullet
@item Provide impoverished proof assistants with a browser
@item Extend the uniform interface of Proof General to theory browsing 
@item Interact closely with proof script writing
@end itemize
The last point is the most important. We should be able to integrate a
search mechanism for proofs of similar theorems, theorems containing
particular constants, etc.




@c
@c
@c APPENDIX: Demonstration instantiation for Isabelle
@c
@c
@node Demonstration Instantiations
@appendix Demonstration Instantiations

This appendix contains the code for the two demonstration
instantiations of Proof General, for Isabelle.

These instantiations make an almost-bare minimum of settings to get
things working.  To add embellishments, you should refer to
the instantiations for other systems distributed with
Proof General.

@menu
* demoisa-easy.el::
* demoisa.el::
@end menu

@node demoisa-easy.el
@section demoisa-easy.el

@lisp
@c FIXME: MAGIC NEEDED TO INCLUDE FILE VERBATIM
@c @includeverbatim ../demoisa/demoisa-easy.el
;; demoisa-easy.el Example Proof General instance for Isabelle
;;
;; Copyright (C) 1999 LFCS Edinburgh. 
;;
;; Author: David Aspinall <da@@dcs.ed.ac.uk>
;;
;; $Id$
;;
;; This is an alternative version of demoisa.el which uses the
;; proof-easy-config macro to do the work of declaring derived modes,
;; etc.  
;;
;; See demoisa.el and the Proof General manual for more documentation.
;;
;; To test this file you must rename it demoisa.el.
;;

(require 'proof-easy-config)            ; easy configure mechanism

(proof-easy-config 
 'demoisa "Isabelle Demo" 
 proof-prog-name		 "isabelle"
 proof-terminal-char             ?\;
 proof-comment-start             "(*"
 proof-comment-end               "*)"
 proof-goal-command-regexp       "^Goal"
 proof-save-command-regexp       "^qed"
 proof-goal-with-hole-regexp     "qed_goal \"\\(\\(.*\\)\\)\""
 proof-save-with-hole-regexp     "qed \"\\(\\(.*\\)\\)\""
 proof-non-undoables-regexp      "undo\\|back"
 proof-goal-command              "Goal \"%s\";"
 proof-save-command              "qed \"%s\";"
 proof-kill-goal-command         "Goal \"PROP no_goal_set\";"
 proof-showproof-command         "pr()"
 proof-undo-n-times-cmd          "pg_repeat undo %s;"
 proof-auto-multiple-files       t
 proof-shell-cd-cmd              "cd \"%s\""
 proof-shell-prompt-pattern      "[ML-=#>]+>? "
 proof-shell-interrupt-regexp    "Interrupt"
 proof-shell-start-goals-regexp  "Level [0-9]"
 proof-shell-end-goals-regexp    "val it"
 proof-shell-quit-cmd            "quit();"
 proof-assistant-home-page    
 "http://www.cl.cam.ac.uk/Research/HVG/Isabelle/"
 proof-shell-annotated-prompt-regexp 
 "^\\(val it = () : unit\n\\)?ML>? "
 proof-shell-error-regexp             
 "\\*\\*\\*\\|^.*Error:\\|^uncaught exception \\|^Exception- "
 proof-shell-init-cmd  
 "fun pg_repeat f 0 = () | pg_repeat f n = (f(); pg_repeat f (n-1));"
 proof-shell-proof-completed-regexp "^No subgoals!"
 proof-shell-eager-annotation-start   
 "^\\[opening \\|^###\\|^Reading")

(provide 'demoisa)
@end lisp

@node demoisa.el
@section demoisa.el

@lisp
@c FIXME: MAGIC NEEDED TO INCLUDE FILE VERBATIM
@c @includeverbatim ../demoisa/demoisa-easy.el
;; demoisa.el Example Proof General instance for Isabelle
;;
;; Copyright (C) 1999 LFCS Edinburgh. 
;;
;; Author: David Aspinall <da@@dcs.ed.ac.uk>
;;
;; $Id$
;;
;; =================================================================
;;
;; See README in this directory for an introduction.
;;
;; Basic configuration is controlled by one line in `proof-site.el'.
;; It has this line in proof-assistant-table:
;;
;;     (demoisa "Isabelle Demo"	"\\.ML$")
;;
;; From this it loads this file "demoisa/demoisa.el" whenever
;; a .ML file is visited, and sets the mode to `demoisa-mode'
;; (defined below).  
;; 
;; I've called this instance "Isabelle Demo Proof General" just to
;; avoid confusion with the real "Isabelle Proof General" in case the
;; demo gets loaded by accident.
;;
;; To make the line above take precedence over the real Isabelle mode
;; later in the table, set PROOFGENERAL_ASSISTANTS=demoisa in the
;; shell before starting Emacs  (or customize proof-assistants).
;;


(require 'proof)			; load generic parts


;; ======== User settings for Isabelle ========
;;
;; Defining variables using customize is pretty easy.
;; You should do it at least for your prover-specific user options.
;;
;; proof-site provides us with two customization groups
;; automatically:  (based on the name of the assistant)
;;
;; 'isabelledemo        -  User options for Isabelle Demo Proof General
;; 'isabelledemo-config -  Configuration of Isabelle Proof General
;;			   (constants, but may be nice to tweak)
;;
;; The first group appears in the menu
;;   ProofGeneral -> Customize -> Isabelledemo 
;; The second group appears in the menu:
;;   ProofGeneral -> Internals -> Isabelledemo config
;;

(defcustom isabelledemo-prog-name "isabelle"
  "*Name of program to run Isabelle."
  :type 'file
  :group 'isabelledemo)

(defcustom isabelledemo-web-page
  "http://www.cl.cam.ac.uk/Research/HVG/isabelle.html"
  "URL of web page for Isabelle."
  :type 'string
  :group 'isabelledemo-config)


;;
;; ======== Configuration of generic modes ========
;;

(defun demoisa-config ()
  "Configure Proof General scripting for Isabelle."
  (setq
   proof-terminal-char		?\;	; ends every command
   proof-comment-start		"(*"
   proof-comment-end		"*)"
   proof-goal-command-regexp    "^Goal"
   proof-save-command-regexp    "^qed"
   proof-goal-with-hole-regexp  "qed_goal \"\\(\\(.*\\)\\)\""
   proof-save-with-hole-regexp  "qed \"\\(\\(.*\\)\\)\""
   proof-non-undoables-regexp   "undo\\|back"
   proof-undo-n-times-cmd	"pg_repeat undo %s;"
   proof-showproof-command	"pr()"
   proof-goal-command		"Goal \"%s\";"
   proof-save-command		"qed \"%s\";"
   proof-kill-goal-command	"Goal \"PROP no_goal_set\";"
   proof-assistant-home-page	isabelledemo-web-page
   proof-auto-multiple-files    t))


(defun demoisa-shell-config ()
  "Configure Proof General shell for Isabelle."
  (setq
   proof-shell-annotated-prompt-regexp   "^\\(val it = () : unit\n\\)?ML>? "
   proof-shell-cd-cmd			"cd \"%s\""
   proof-shell-prompt-pattern		"[ML-=#>]+>? "
   proof-shell-interrupt-regexp         "Interrupt"
   proof-shell-error-regexp		"\\*\\*\\*\\|^.*Error:\\|^uncaught exception \\|^Exception- "
   proof-shell-start-goals-regexp	"Level [0-9]"
   proof-shell-end-goals-regexp		"val it"
   proof-shell-proof-completed-regexp   "^No subgoals!"
   proof-shell-eager-annotation-start   "^\\[opening \\|^###\\|^Reading"
   proof-shell-init-cmd  ; define a utility function, in a lib somewhere?
   "fun pg_repeat f 0 = () 
      | pg_repeat f n = (f(); pg_repeat f (n-1));"
   proof-shell-quit-cmd			"quit();"))



;;
;; ======== Defining the derived modes ========
;;

;; The name of the script mode is always <proofsym>-script,
;; but the others can be whatever you like.
;;
;; The derived modes set the variables, then call the
;; <mode>-config-done function to complete configuration.

(define-derived-mode demoisa-mode proof-mode
    "Isabelle Demo script" nil
    (demoisa-config)
    (proof-config-done))

(define-derived-mode demoisa-shell-mode proof-shell-mode
   "Isabelle Demo shell" nil
   (demoisa-shell-config)
   (proof-shell-config-done))

(define-derived-mode demoisa-response-mode proof-response-mode
  "Isabelle Demo response" nil
  (proof-response-config-done))

(define-derived-mode demoisa-goals-mode proof-goals-mode
  "Isabelle Demo goals" nil
  (proof-goals-config-done))

;; The response buffer and goals buffer modes defined above are
;; trivial.  In fact, we don't need to define them at all -- they
;; would simply default to "proof-response-mode" and "pbp-mode".

;; A more sophisticated instantiation might set font-lock-keywords to
;; add highlighting, or some of the proof by pointing markup
;; configuration for the goals buffer.

;; The final piece of magic here is a hook which configures settings
;; to get the proof shell running.  Proof General needs to know the
;; name of the program to run, and the modes for the shell, response,
;; and goals buffers.

(add-hook 'proof-pre-shell-start-hook 'demoisa-pre-shell-start)

(defun demoisa-pre-shell-start ()
  (setq proof-prog-name		isabelledemo-prog-name)
  (setq proof-mode-for-shell    'demoisa-shell-mode)
  (setq proof-mode-for-response 'demoisa-response-mode)
  (setq proof-mode-for-goals	'demoisa-goals-mode))

(provide 'demoisa)
@end lisp




@node Function Index
@unnumbered Function and Command Index
@printindex fn

@node Variable Index
@unnumbered Variable and User Option Index
@printindex vr

@c Nothing in this one!
@c @node Keystroke Index
@c @unnumbered Keystroke Index
@c @printindex ky

@node Concept Index
@unnumbered Concept Index
@printindex cp

@page
@contents
@bye