diff options
Diffstat (limited to 'doc/sphinx/proof-engine')
| -rw-r--r-- | doc/sphinx/proof-engine/detailed-tactic-examples.rst | 13 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/ltac.rst | 47 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/proof-handling.rst | 70 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/ssreflect-proof-language.rst | 172 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/tactics.rst | 1131 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/vernacular-commands.rst | 33 |
6 files changed, 757 insertions, 709 deletions
diff --git a/doc/sphinx/proof-engine/detailed-tactic-examples.rst b/doc/sphinx/proof-engine/detailed-tactic-examples.rst index 78719c1ef1..72dd79d930 100644 --- a/doc/sphinx/proof-engine/detailed-tactic-examples.rst +++ b/doc/sphinx/proof-engine/detailed-tactic-examples.rst @@ -21,7 +21,7 @@ applied to the abstracted instance and after simplification of the equalities we get the expected goals. The abstracting tactic is called generalize_eqs and it takes as -argument an hypothesis to generalize. It uses the JMeq datatype +argument a hypothesis to generalize. It uses the JMeq datatype defined in Coq.Logic.JMeq, hence we need to require it before. For example, revisiting the first example of the inversion documentation: @@ -341,8 +341,7 @@ involves conditional rewritings and shows how to deal with them using the optional tactic of the ``Hint Rewrite`` command. -.. example:: - Ackermann function +.. example:: Ackermann function .. coqtop:: in reset @@ -370,8 +369,7 @@ the optional tactic of the ``Hint Rewrite`` command. autorewrite with base0 using try reflexivity. -.. example:: - MacCarthy function +.. example:: MacCarthy function .. coqtop:: in reset @@ -475,9 +473,8 @@ corresponding left-hand side and call yourself recursively on sub- terms. If there is no match, we are at a leaf: return the corresponding constructor (here ``f_const``) applied to the term. -.. exn:: quote: not a simple fixpoint - - Happens when ``quote`` is not able to perform inversion properly. +When ``quote`` is not able to perform inversion properly, it will error out with +:exn:`quote: not a simple fixpoint`. Introducing variables map diff --git a/doc/sphinx/proof-engine/ltac.rst b/doc/sphinx/proof-engine/ltac.rst index dc355fa013..7608ea7245 100644 --- a/doc/sphinx/proof-engine/ltac.rst +++ b/doc/sphinx/proof-engine/ltac.rst @@ -144,10 +144,11 @@ mode but it can also be used in toplevel definitions as shown below. : | `integer` (< | <= | > | >=) `integer` selector : [`ident`] : | `integer` - : (`integer` | `integer` - `integer`), ..., (`integer` | `integer` - `integer`) + : | (`integer` | `integer` - `integer`), ..., (`integer` | `integer` - `integer`) toplevel_selector : `selector` - : | `all` - : | `par` + : | all + : | par + : | ! .. productionlist:: coq top : [Local] Ltac `ltac_def` with ... with `ltac_def` @@ -177,7 +178,7 @@ Sequence A sequence is an expression of the following form: -.. tacn:: @expr ; @expr +.. tacn:: @expr__1 ; @expr__2 :name: ltac-seq The expression :n:`@expr__1` is evaluated to :n:`v__1`, which must be @@ -207,11 +208,11 @@ following form: were given. For instance, ``[> | auto]`` is a shortcut for ``[> idtac | auto ]``. - .. tacv:: [> {*| @expr} | @expr .. | {*| @expr}] + .. tacv:: [> {*| @expr__i} | @expr .. | {*| @expr__j}] - In this variant, token:`expr` is used for each goal coming after those - covered by the first list of :n:`@expr` but before those coevered by the - last list of :n:`@expr`. + In this variant, :n:`@expr` is used for each goal coming after those + covered by the list of :n:`@expr__i` but before those covered by the + list of :n:`@expr__j`. .. tacv:: [> {*| @expr} | .. | {*| @expr}] @@ -225,11 +226,11 @@ following form: tactic is not run at all. A tactic which expects multiple goals, such as ``swap``, would act as if a single goal is focused. - .. tacv:: expr ; [{*| @expr}] + .. tacv:: @expr__0 ; [{*| @expr__i}] This variant of local tactic application is paired with a sequence. In this - variant, there must be as many :n:`@expr` in the list as goals generated - by the application of the first :n:`@expr` to each of the individual goals + variant, there must be as many :n:`@expr__i` as goals generated + by the application of :n:`@expr__0` to each of the individual goals independently. All the above variants work in this form too. Formally, :n:`@expr ; [ ... ]` is equivalent to :n:`[> @expr ; [> ... ] .. ]`. @@ -247,20 +248,20 @@ focused goals with: We can also use selectors as a tactical, which allows to use them nested in a tactic expression, by using the keyword ``only``: - .. tacv:: only selector : expr + .. tacv:: only @selector : @expr :name: only ... : ... - When selecting several goals, the tactic expr is applied globally to all + When selecting several goals, the tactic :token:`expr` is applied globally to all selected goals. .. tacv:: [@ident] : @expr - In this variant, :n:`@expr` is applied locally to a goal previously named + In this variant, :token:`expr` is applied locally to a goal previously named by the user (see :ref:`existential-variables`). .. tacv:: @num : @expr - In this variant, :n:`@expr` is applied locally to the :token:`num`-th goal. + In this variant, :token:`expr` is applied locally to the :token:`num`-th goal. .. tacv:: {+, @num-@num} : @expr @@ -271,13 +272,13 @@ focused goals with: .. tacv:: all: @expr :name: all: ... - In this variant, :n:`@expr` is applied to all focused goals. ``all:`` can only + In this variant, :token:`expr` is applied to all focused goals. ``all:`` can only be used at the toplevel of a tactic expression. .. tacv:: !: @expr - In this variant, if exactly one goal is focused :n:`expr` is - applied to it. Otherwise the tactical fails. ``!:`` can only be + In this variant, if exactly one goal is focused, :token:`expr` is + applied to it. Otherwise the tactic fails. ``!:`` can only be used at the toplevel of a tactic expression. .. tacv:: par: @expr @@ -390,7 +391,7 @@ tactic to work (i.e. which does not fail) among a panel of tactics: focused goal independently and stops if it succeeds; otherwise it tries to apply :n:`v__2` and so on. It fails when there is no applicable tactic. In other words, - :n:`first [@expr__1 | ... | @expr__n]` behaves, in each goal, as the the first + :n:`first [@expr__1 | ... | @expr__n]` behaves, in each goal, as the first :n:`v__i` to have *at least* one success. .. exn:: No applicable tactic. @@ -555,9 +556,9 @@ Failing The number is the failure level. If no level is specified, it defaults to 0. The level is used by :tacn:`try`, :tacn:`repeat`, :tacn:`match goal` and the branching tacticals. If 0, it makes :tacn:`match goal` consider the next clause - (backtracking). If non zero, the current :tacn:`match goal` block, :tacn:`try`, + (backtracking). If nonzero, the current :tacn:`match goal` block, :tacn:`try`, :tacn:`repeat`, or branching command is aborted and the level is decremented. In - the case of :n:`+`, a non-zero level skips the first backtrack point, even if + the case of :n:`+`, a nonzero level skips the first backtrack point, even if the call to :n:`fail @num` is not enclosed in a :n:`+` command, respecting the algebraic identity. @@ -862,7 +863,7 @@ We can perform pattern matching on goals using the following expression: :name: match goal If each hypothesis pattern :n:`hyp`\ :sub:`1,i`, with i = 1, ..., m\ :sub:`1` is - matched (non-linear first-order unification) by an hypothesis of the + matched (non-linear first-order unification) by a hypothesis of the goal and if :n:`cpattern_1` is matched by the conclusion of the goal, then :n:`@expr__1` is evaluated to :n:`v__1` by substituting the pattern matching to the metavariables and the real hypothesis names @@ -988,7 +989,7 @@ Manipulating untyped terms An untyped term, in |Ltac|, can contain references to hypotheses or to |Ltac| variables containing typed or untyped terms. An untyped term can be - type-checked using the function type_term whose argument is parsed as an + type checked using the function type_term whose argument is parsed as an untyped term and returns a well-typed term which can be used in tactics. Untyped terms built using :n:`uconstr :` can also be used as arguments to the diff --git a/doc/sphinx/proof-engine/proof-handling.rst b/doc/sphinx/proof-engine/proof-handling.rst index 44376080c3..b1e769c571 100644 --- a/doc/sphinx/proof-engine/proof-handling.rst +++ b/doc/sphinx/proof-engine/proof-handling.rst @@ -84,7 +84,7 @@ list of assertion commands is given in :ref:`Assertions`. The command :name: Defined Same as :cmd:`Qed` but the proof is then declared transparent, which means - that its content can be explicitly used for type-checking and that it can be + that its content can be explicitly used for type checking and that it can be unfolded in conversion tactics (see :ref:`performingcomputations`, :cmd:`Opaque`, :cmd:`Transparent`). @@ -315,6 +315,9 @@ Navigation in the proof tree .. _curly-braces: +.. index:: { + } + .. cmd:: %{ %| %} The command ``{`` (without a terminating period) focuses on the first @@ -329,20 +332,47 @@ Navigation in the proof tree .. cmdv:: @num: %{ - This focuses on the :token:`num` th subgoal to prove. + This focuses on the :token:`num`\-th subgoal to prove. + + .. cmdv:: [@ident]: %{ + + This focuses on the named goal :token:`ident`. + + .. note:: + + Goals are just existential variables and existential variables do not + get a name by default. You can give a name to a goal by using :n:`refine ?[@ident]`. - Error messages: + .. seealso:: :ref:`existential-variables` + + .. example:: + + This can also be a way of focusing on a shelved goal, for instance: + + .. coqtop:: all + + Goal exists n : nat, n = n. + eexists ?[x]. + reflexivity. + [x]: exact 0. + Qed. .. exn:: This proof is focused, but cannot be unfocused this way. You are trying to use ``}`` but the current subproof has not been fully solved. - .. exn:: No such goal. - :name: No such goal. (Focusing) + .. exn:: No such goal (@num). + :undocumented: + + .. exn:: No such goal (@ident). + :undocumented: + + .. exn:: Brackets do not support multi-goal selectors. - .. exn:: Brackets only support the single numbered goal selector. + Brackets are used to focus on a single goal given either by its position + or by its name if it has one. - See also error messages about bullets below. + .. seealso:: The error messages about bullets below. .. _bullets: @@ -358,8 +388,10 @@ same bullet ``b``. See the example below. Different bullets can be used to nest levels. The scope of bullet does not go beyond enclosing ``{`` and ``}``, so bullets can be reused as further -nesting levels provided they are delimited by these. Available bullets -are ``-``, ``+``, ``*``, ``--``, ``++``, ``**``, ``---``, ``+++``, ``***``, ... (without a terminating period). +nesting levels provided they are delimited by these. Bullets are made of +repeated ``-``, ``+`` or ``*`` symbols: + +.. prodn:: bullet ::= {+ - } %| {+ + } %| {+ * } Note again that when a focused goal is proved a message is displayed together with a suggestion about the right bullet or ``}`` to unfocus it @@ -375,6 +407,7 @@ or focus the next one. The following example script illustrates all these features: .. example:: + .. coqtop:: all Goal (((True /\ True) /\ True) /\ True) /\ True. @@ -391,19 +424,23 @@ The following example script illustrates all these features: - assert True. { trivial. } assumption. + Qed. +.. exn:: Wrong bullet @bullet__1: Current bullet @bullet__2 is not finished. -.. exn:: Wrong bullet @bullet1: Current bullet @bullet2 is not finished. + Before using bullet :n:`@bullet__1` again, you should first finish proving + the current focused goal. + Note that :n:`@bullet__1` and :n:`@bullet__2` may be the same. - Before using bullet :n:`@bullet1` again, you should first finish proving the current focused goal. Note that :n:`@bullet1` and :n:`@bullet2` may be the same. +.. exn:: Wrong bullet @bullet__1: Bullet @bullet__2 is mandatory here. -.. exn:: Wrong bullet @bullet1: Bullet @bullet2 is mandatory here. - - You must put :n:`@bullet2` to focus next goal. No other bullet is allowed here. + You must put :n:`@bullet__2` to focus on the next goal. No other bullet is + allowed here. .. exn:: No such goal. Focus next goal with bullet @bullet. - You tried to apply a tactic but no goals were under focus. Using :n:`@bullet` is mandatory here. + You tried to apply a tactic but no goals were under focus. + Using :n:`@bullet` is mandatory here. .. exn:: No such goal. Try unfocusing with %{. @@ -432,7 +469,7 @@ Requesting information .. cmdv:: Show @num - Displays only the :token:`num` th subgoal. + Displays only the :token:`num`\-th subgoal. .. exn:: No such goal. @@ -511,6 +548,7 @@ Requesting information :token:`ident` .. example:: + .. coqtop:: all Show Match nat. diff --git a/doc/sphinx/proof-engine/ssreflect-proof-language.rst b/doc/sphinx/proof-engine/ssreflect-proof-language.rst index 6fb73a030f..7c3ea1a28c 100644 --- a/doc/sphinx/proof-engine/ssreflect-proof-language.rst +++ b/doc/sphinx/proof-engine/ssreflect-proof-language.rst @@ -37,7 +37,7 @@ bookkeeping is performed on the conclusion of the goal, using for that purpose a couple of syntactic constructions behaving similar to tacticals (and often named as such in this chapter). The ``:`` tactical moves hypotheses from the context to the conclusion, while ``=>`` moves hypotheses from the -conclusion to the context, and ``in`` moves back and forth an hypothesis from the +conclusion to the context, and ``in`` moves back and forth a hypothesis from the context to the conclusion for the time of applying an action to it. While naming hypotheses is commonly done by means of an ``as`` clause in the @@ -303,7 +303,7 @@ the ``if`` construct to all binary data types; compare The latter appears to be marginally shorter, but it is quite ambiguous, and indeed often requires an explicit annotation -``(term : {_} + {_})`` to type-check, which evens the character count. +``(term : {_} + {_})`` to type check, which evens the character count. Therefore, |SSR| restricts by default the condition of a plain if construct to the standard ``bool`` type; this avoids spurious type @@ -385,7 +385,7 @@ expressions such as Unfortunately, such higher-order expressions are quite frequent in representation functions, especially those which use |Coq|'s -``Structures`` to emulate Haskell type classes. +``Structures`` to emulate Haskell typeclasses. Therefore, |SSR| provides a variant of |Coq|’s implicit argument declaration, which causes |Coq| to fill in some implicit parameters at @@ -1285,7 +1285,7 @@ catch the appropriate number of wildcards to be inserted. Note that this use of the refine tactic implies that the tactic tries to match the goal up to expansion of constants and evaluation of subterms. -|SSR|’s apply has a special behaviour on goals containing +|SSR|’s apply has a special behavior on goals containing existential metavariables of sort Prop. .. example:: @@ -2064,26 +2064,27 @@ is equivalent to: (see section :ref:`discharge_ssr` for the documentation of the apply: combination). -Warning The list of tactics, possibly chained by semicolons, that -follows a by keyword is considered as a parenthesized block applied to -the current goal. Hence for example if the tactic: +.. warning:: -.. coqtop:: in + The list of tactics (possibly chained by semicolons) that + follows the ``by`` keyword is considered to be a parenthesized block applied to + the current goal. Hence for example if the tactic: - by rewrite my_lemma1. + .. coqtop:: in -succeeds, then the tactic: + by rewrite my_lemma1. -.. coqtop:: in + succeeds, then the tactic: - by rewrite my_lemma1; apply my_lemma2. + .. coqtop:: in -usually fails since it is equivalent to: + by rewrite my_lemma1; apply my_lemma2. -.. coqtop:: in + usually fails since it is equivalent to: - by (rewrite my_lemma1; apply my_lemma2). + .. coqtop:: in + by (rewrite my_lemma1; apply my_lemma2). .. _selectors_ssr: @@ -2522,7 +2523,8 @@ After the :token:`i_pattern`, a list of binders is allowed. .. coqtop:: reset - From Coq Require Import ssreflect Omega. + From Coq Require Import ssreflect. + From Coq Require Import Omega. Set Implicit Arguments. Unset Strict Implicit. Unset Printing Implicit Defensive. @@ -2552,12 +2554,9 @@ copying the goal itself. .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. .. coqtop:: all @@ -2581,12 +2580,9 @@ context entry name. .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. Set Printing Depth 15. .. coqtop:: all @@ -2601,20 +2597,13 @@ context entry name. Note that the sub-term produced by ``omega`` is in general huge and uninteresting, and hence one may want to hide it. For this purpose the ``[: name ]`` intro pattern and the tactic -``abstract`` (see page :ref:`abstract_ssr`) are provided. +``abstract`` (see :ref:`abstract_ssr`) are provided. .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. - - Inductive Ord n := Sub x of x < n. - Notation "'I_ n" := (Ord n) (at level 8, n at level 2, format "''I_' n"). - Arguments Sub {_} _ _. + Abort All. .. coqtop:: all @@ -2629,16 +2618,9 @@ with have and an explicit term, they must be used as follows: .. example:: - .. coqtop:: reset - - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + .. coqtop:: none - Inductive Ord n := Sub x of x < n. - Notation "'I_ n" := (Ord n) (at level 8, n at level 2, format "''I_' n"). - Arguments Sub {_} _ _. + Abort All. .. coqtop:: all @@ -2659,16 +2641,9 @@ makes use of it). .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. - - Inductive Ord n := Sub x of x < n. - Notation "'I_ n" := (Ord n) (at level 8, n at level 2, format "''I_' n"). - Arguments Sub {_} _ _. + Abort All. .. coqtop:: all @@ -2679,18 +2654,15 @@ Last, notice that the use of intro patterns for abstract constants is orthogonal to the transparent flag ``@`` for have. -The have tactic and type classes resolution +The have tactic and typeclass resolution ``````````````````````````````````````````` -Since |SSR| 1.5 the have tactic behaves as follows with respect to -type classes inference. +Since |SSR| 1.5 the ``have`` tactic behaves as follows with respect to +typeclass inference. - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. Axiom ty : Type. Axiom t : ty. @@ -2728,7 +2700,7 @@ type classes inference. .. opt:: SsrHave NoTCResolution - This option restores the behavior of |SSR| 1.4 and below (never resolve type classes). + This option restores the behavior of |SSR| 1.4 and below (never resolve typeclasses). Variants: the suff and wlog tactics ``````````````````````````````````` @@ -2766,12 +2738,9 @@ The ``have`` modifier can follow the ``suff`` tactic. .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. Axioms G P : Prop. .. coqtop:: all @@ -2839,12 +2808,9 @@ are unique. .. example:: - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. .. coqtop:: all @@ -2935,12 +2901,10 @@ illustrated in the following example. the pattern ``id (addx x)``, that would produce the following first subgoal - .. coqtop:: reset + .. coqtop:: none - From Coq Require Import ssreflect Omega. - Set Implicit Arguments. - Unset Strict Implicit. - Unset Printing Implicit Defensive. + Abort All. + From Coq Require Import Omega. Section Test. Variable x : nat. Definition addx z := z + x. @@ -3046,6 +3010,15 @@ An :token:`r_item` can be: is equivalent to: ``change term1 with term2.`` If ``term2`` is a single constant and ``term1`` head symbol is not ``term2``, then the head symbol of ``term1`` is repeatedly unfolded until ``term2`` appears. ++ A :token:`term`, which can be: + + A term whose type has the form: + ``forall (x1 : A1 )…(xn : An ), eq term1 term2`` where + ``eq`` is the Leibniz equality or a registered setoid + equality. + + A list of terms ``(t1 ,…,tn)``, each ``ti`` having a type above. + The tactic: ``rewrite r_prefix (t1 ,…,tn ).`` + is equivalent to: ``do [rewrite r_prefix t1 | … | rewrite r_prefix tn ].`` + + An anonymous rewrite lemma ``(_ : term)``, where term has a type as above. tactic: ``rewrite (_ : term)`` is in fact synonym of: ``cutrewrite (term).``. .. example:: @@ -3063,9 +3036,10 @@ An :token:`r_item` can be: Lemma test x : ddouble x = 4 * x. rewrite [ddouble _]/double. - *Warning* The |SSR| - terms containing holes are *not* typed as abstractions in this - context. Hence the following script fails. + .. warning:: + + The |SSR| terms containing holes are *not* typed as + abstractions in this context. Hence the following script fails. .. coqtop:: none @@ -3087,17 +3061,6 @@ An :token:`r_item` can be: rewrite -[f y x]/(y + _). -+ A :token:`term`, which can be: - - + A term whose type has the form: - ``forall (x1 : A1 )…(xn : An ), eq term1 term2`` where - ``eq`` is the Leibniz equality or a registered setoid - equality. - + A list of terms ``(t1 ,…,tn)``, each ``ti`` having a type above. - The tactic: ``rewrite r_prefix (t1 ,…,tn ).`` - is equivalent to: ``do [rewrite r_prefix t1 | … | rewrite r_prefix tn ].`` - + An anonymous rewrite lemma ``(_ : term)``, where term has a type as above. tactic: ``rewrite (_ : term)`` is in fact synonym of: ``cutrewrite (term).``. - Remarks and examples ~~~~~~~~~~~~~~~~~~~~ @@ -3738,20 +3701,22 @@ Note that ``nosimpl bar`` is simply notation for a term that reduces to ``bar``; hence ``unfold foo`` will replace ``foo`` by ``bar``, and ``fold foo`` will replace ``bar`` by ``foo``. -*Warning* The ``nosimpl`` trick only works if no reduction is apparent in -``t``; in particular, the declaration: +.. warning:: -.. coqtop:: in + The ``nosimpl`` trick only works if no reduction is apparent in + ``t``; in particular, the declaration: - Definition foo x := nosimpl (bar x). + .. coqtop:: in -will usually not work. Anyway, the common practice is to tag only the -function, and to use the following definition, which blocks the -reduction as expected: + Definition foo x := nosimpl (bar x). -.. coqtop:: in + will usually not work. Anyway, the common practice is to tag only the + function, and to use the following definition, which blocks the + reduction as expected: - Definition foo x := nosimpl bar x. + .. coqtop:: in + + Definition foo x := nosimpl bar x. A standard example making this technique shine is the case of arithmetic operations. We define for instance: @@ -4632,6 +4597,7 @@ bookkeeping steps. .. example:: + The following example use the ``~~`` prenex notation for boolean negation: @@ -4793,7 +4759,7 @@ equivalence property has been defined. Lemma andE (b1 b2 : bool) : (b1 /\ b2) <-> (b1 && b2). -Let us compare the respective behaviours of ``andE`` and ``andP``. +Let us compare the respective behaviors of ``andE`` and ``andP``. .. example:: @@ -4906,7 +4872,7 @@ The term , called the *view lemma* can be: Let ``top`` be the top assumption in the goal. -There are three steps in the behaviour of an assumption view tactic: +There are three steps in the behavior of an assumption view tactic: + It first introduces ``top``. + If the type of :token:`term` is neither a double implication nor an diff --git a/doc/sphinx/proof-engine/tactics.rst b/doc/sphinx/proof-engine/tactics.rst index 9b4d724e02..241cdf5eea 100644 --- a/doc/sphinx/proof-engine/tactics.rst +++ b/doc/sphinx/proof-engine/tactics.rst @@ -113,26 +113,26 @@ Occurrence sets and occurrence clauses An occurrence clause is a modifier to some tactics that obeys the following syntax: -.. _tactic_occurence_grammar: - .. productionlist:: `sentence` - occurence_clause : in `goal_occurences` - goal_occurences : [ident [`at_occurences`], ... , ident [`at_occurences`] [|- [* [`at_occurences`]]]] - :| * |- [* [`at_occurences`]] + occurrence_clause : in `goal_occurrences` + goal_occurrences : [`ident` [`at_occurrences`], ... , ident [`at_occurrences`] [|- [* [`at_occurrences`]]]] + :| * |- [* [`at_occurrences`]] :| * at_occurrences : at `occurrences` - occurences : [-] `num` ... `num` - -The role of an occurrence clause is to select a set of occurrences of a term in -a goal. In the first case, the :n:`@ident {? at {* num}}` parts indicate that -occurrences have to be selected in the hypotheses named :n:`@ident`. If no -numbers are given for hypothesis :n:`@ident`, then all the occurrences of `term` -in the hypothesis are selected. If numbers are given, they refer to occurrences -of `term` when the term is printed using option :opt:`Printing All`, counting -from left to right. In particular, occurrences of `term` in implicit arguments -(see :ref:`ImplicitArguments`) or coercions (see :ref:`Coercions`) are counted. - -If a minus sign is given between at and the list of occurrences, it + occurrences : [-] `num` ... `num` + +The role of an occurrence clause is to select a set of occurrences of a term +in a goal. In the first case, the :n:`@ident {? at {* num}}` parts indicate +that occurrences have to be selected in the hypotheses named :token:`ident`. +If no numbers are given for hypothesis :token:`ident`, then all the +occurrences of :token:`term` in the hypothesis are selected. If numbers are +given, they refer to occurrences of :token:`term` when the term is printed +using option :opt:`Printing All`, counting from left to right. In particular, +occurrences of :token:`term` in implicit arguments +(see :ref:`ImplicitArguments`) or coercions (see :ref:`Coercions`) are +counted. + +If a minus sign is given between ``at`` and the list of occurrences, it negates the condition so that the clause denotes all the occurrences except the ones explicitly mentioned after the minus sign. @@ -146,18 +146,20 @@ of term are selected in every hypothesis. In the first and second case, if ``*`` is mentioned on the right of ``|-``, the occurrences of the conclusion of the goal have to be selected. If some numbers are given, then only the occurrences denoted by these numbers are selected. If -no numbers are given, all occurrences of :n:`@term` in the goal are selected. +no numbers are given, all occurrences of :token:`term` in the goal are selected. Finally, the last notation is an abbreviation for ``* |- *``. Note also that ``|-`` is optional in the first case when no ``*`` is given. -Here are some tactics that understand occurrence clauses: :tacn:`set`, :tacn:`remember` -, :tacn:`induction`, :tacn:`destruct`. +Here are some tactics that understand occurrence clauses: :tacn:`set`, +:tacn:`remember`, :tacn:`induction`, :tacn:`destruct`. + + +.. seealso:: + :ref:`Managingthelocalcontext`, :ref:`caseanalysisandinduction`, + :ref:`printing_constructions_full`. -See also: :ref:`Managingthelocalcontext`, -:ref:`caseanalysisandinduction`, -:ref:`printing_constructions_full`. .. _applyingtheorems: @@ -173,40 +175,45 @@ Applying theorems :ref:`Conversion-rules`). .. exn:: Not an exact proof. + :undocumented: .. tacv:: eexact @term. :name: eexact - This tactic behaves like exact but is able to handle terms and goals with - meta-variables. + This tactic behaves like :tacn:`exact` but is able to handle terms and + goals with existential variables. .. tacn:: assumption :name: assumption - This tactic looks in the local context for an hypothesis which type is equal to - the goal. If it is the case, the subgoal is proved. Otherwise, it fails. + This tactic looks in the local context for a hypothesis whose type is + convertible to the goal. If it is the case, the subgoal is proved. + Otherwise, it fails. .. exn:: No such assumption. + :undocumented: .. tacv:: eassumption :name: eassumption - This tactic behaves like assumption but is able to handle goals with - meta-variables. + This tactic behaves like :tacn:`assumption` but is able to handle + goals with existential variables. .. tacn:: refine @term :name: refine This tactic applies to any goal. It behaves like :tacn:`exact` with a big - difference: the user can leave some holes (denoted by ``_`` or ``(_:type)``) in - the term. :tacn:`refine` will generate as many subgoals as there are holes in - the term. The type of holes must be either synthesized by the system - or declared by an explicit cast like ``(_:nat->Prop)``. Any subgoal that + difference: the user can leave some holes (denoted by ``_`` + or :n:`(_ : @type)`) in the term. :tacn:`refine` will generate as many + subgoals as there are holes in the term. The type of holes must be either + synthesized by the system or declared by an explicit cast + like ``(_ : nat -> Prop)``. Any subgoal that occurs in other subgoals is automatically shelved, as if calling :tacn:`shelve_unifiable`. This low-level tactic can be useful to advanced users. .. example:: + .. coqtop:: reset all Inductive Option : Set := @@ -214,16 +221,13 @@ Applying theorems | Ok : bool -> Option. Definition get : forall x:Option, x <> Fail -> bool. - - refine - (fun x:Option => - match x return x <> Fail -> bool with - | Fail => _ - | Ok b => fun _ => b - end). - - intros; absurd (Fail = Fail); trivial. - + refine + (fun x:Option => + match x return x <> Fail -> bool with + | Fail => _ + | Ok b => fun _ => b + end). + intros; absurd (Fail = Fail); trivial. Defined. .. exn:: Invalid argument. @@ -251,41 +255,43 @@ Applying theorems .. tacv:: notypeclasses refine @term :name: notypeclasses refine - This tactic behaves like :tacn:`refine` except it performs typechecking without + This tactic behaves like :tacn:`refine` except it performs type checking without resolution of typeclasses. .. tacv:: simple notypeclasses refine @term :name: simple notypeclasses refine - This tactic behaves like :tacn:`simple refine` except it performs typechecking + This tactic behaves like :tacn:`simple refine` except it performs type checking without resolution of typeclasses. .. tacn:: apply @term :name: apply - This tactic applies to any goal. The argument term is a term well-formed in the - local context. The tactic apply tries to match the current goal against the - conclusion of the type of term. If it succeeds, then the tactic returns as many - subgoals as the number of non-dependent premises of the type of term. If the - conclusion of the type of term does not match the goal *and* the conclusion is - an inductive type isomorphic to a tuple type, then each component of the tuple - is recursively matched to the goal in the left-to-right order. - - The tactic :tacn:`apply` relies on first-order unification with dependent types - unless the conclusion of the type of :token:`term` is of the form :g:`P (t`:sub:`1` - :g:`...` :g:`t`:sub:`n` :g:`)` with `P` to be instantiated. In the latter case, the behavior - depends on the form of the goal. If the goal is of the form - :g:`(fun x => Q) u`:sub:`1` :g:`...` :g:`u`:sub:`n` and the :g:`t`:sub:`i` and - :g:`u`:sub:`i` unifies, then :g:`P` is taken to be :g:`(fun x => Q)`. Otherwise, - :tacn:`apply` tries to define :g:`P` by abstracting over :g:`t`:sub:`1` :g:`...` - :g:`t`:sub:`n` in the goal. See :tacn:`pattern` to transform the goal so that it - gets the form :g:`(fun x => Q) u`:sub:`1` :g:`...` :g:`u`:sub:`n`. - - .. exn:: Unable to unify ... with ... . - - The apply tactic failed to match the conclusion of :token:`term` and the - current goal. You can help the apply tactic by transforming your goal with - the :tacn:`change` or :tacn:`pattern` tactics. + This tactic applies to any goal. The argument term is a term well-formed in + the local context. The tactic :tacn:`apply` tries to match the current goal + against the conclusion of the type of :token:`term`. If it succeeds, then + the tactic returns as many subgoals as the number of non-dependent premises + of the type of term. If the conclusion of the type of :token:`term` does + not match the goal *and* the conclusion is an inductive type isomorphic to + a tuple type, then each component of the tuple is recursively matched to + the goal in the left-to-right order. + + The tactic :tacn:`apply` relies on first-order unification with dependent + types unless the conclusion of the type of :token:`term` is of the form + :n:`P (t__1 ... t__n)` with ``P`` to be instantiated. In the latter case, + the behavior depends on the form of the goal. If the goal is of the form + :n:`(fun x => Q) u__1 ... u__n` and the :n:`t__i` and :n:`u__i` unify, + then :g:`P` is taken to be :g:`(fun x => Q)`. Otherwise, :tacn:`apply` + tries to define :g:`P` by abstracting over :g:`t_1 ... t__n` in the goal. + See :tacn:`pattern` to transform the goal so that it + gets the form :n:`(fun x => Q) u__1 ... u__n`. + + .. exn:: Unable to unify @term with @term. + + The :tacn:`apply` tactic failed to match the conclusion of :token:`term` + and the current goal. You can help the :tacn:`apply` tactic by + transforming your goal with the :tacn:`change` or :tacn:`pattern` + tactics. .. exn:: Unable to find an instance for the variables {+ @ident}. @@ -301,6 +307,7 @@ Applying theorems according to the order of these dependent premises of the type of term. .. exn:: Not the right number of missing arguments. + :undocumented: .. tacv:: apply @term with @bindings_list @@ -310,11 +317,9 @@ Applying theorems .. tacv:: apply {+, @term} - This is a shortcut for :n:`apply @term`:sub:`1` - :n:`; [.. | ... ; [ .. | apply @term`:sub:`n` :n:`] ... ]`, - i.e. for the successive applications of :token:`term`:sub:`i+1` on the last subgoal - generated by :n:`apply @term`:sub:`i` , starting from the application of - :token:`term`:sub:`1`. + This is a shortcut for :n:`apply @term__1; [.. | ... ; [ .. | apply @term__n] ... ]`, + i.e. for the successive applications of :n:`@term`:sub:`i+1` on the last subgoal + generated by :n:`apply @term__i` , starting from the application of :n:`@term__1`. .. tacv:: eapply @term :name: eapply @@ -326,7 +331,6 @@ Applying theorems intended to be found later in the proof. .. tacv:: simple apply @term. - :name: simple apply This behaves like :tacn:`apply` but it reasons modulo conversion only on subterms that contain no variables to instantiate. For instance, the following example @@ -348,8 +352,8 @@ Applying theorems does. .. tacv:: {? simple} apply {+, @term {? with @bindings_list}} - .. tacv:: {? simple} eapply {+, @term {? with @bindings_list}} - :name: simple eapply + {? simple} eapply {+, @term {? with @bindings_list}} + :name: simple apply; simple eapply This summarizes the different syntaxes for :tacn:`apply` and :tacn:`eapply`. @@ -364,8 +368,10 @@ Applying theorems sequence ``cut B. 2:apply H.`` where ``cut`` is described below. .. warn:: When @term contains more than one non dependent product the tactic lapply only takes into account the first product. + :undocumented: .. example:: + Assume we have a transitive relation ``R`` on ``nat``: .. coqtop:: reset in @@ -453,164 +459,151 @@ Applying theorems .. tacn:: apply @term in @ident :name: apply ... in - This tactic applies to any goal. The argument ``term`` is a term well-formed in - the local context and the argument :n:`@ident` is an hypothesis of the context. - The tactic ``apply term in ident`` tries to match the conclusion of the type - of :n:`@ident` against a non-dependent premise of the type of ``term``, trying - them from right to left. If it succeeds, the statement of hypothesis - :n:`@ident` is replaced by the conclusion of the type of ``term``. The tactic - also returns as many subgoals as the number of other non-dependent premises - in the type of ``term`` and of the non-dependent premises of the type of - :n:`@ident`. If the conclusion of the type of ``term`` does not match the goal - *and* the conclusion is an inductive type isomorphic to a tuple type, then + This tactic applies to any goal. The argument :token:`term` is a term + well-formed in the local context and the argument :token:`ident` is an + hypothesis of the context. + The tactic :n:`apply @term in @ident` tries to match the conclusion of the + type of :token:`ident` against a non-dependent premise of the type + of :token:`term`, trying them from right to left. If it succeeds, the + statement of hypothesis :token:`ident` is replaced by the conclusion of + the type of :token:`term`. The tactic also returns as many subgoals as the + number of other non-dependent premises in the type of :token:`term` and of + the non-dependent premises of the type of :token:`ident`. If the conclusion + of the type of :token:`term` does not match the goal *and* the conclusion + is an inductive type isomorphic to a tuple type, then the tuple is (recursively) decomposed and the first component of the tuple of which a non-dependent premise matches the conclusion of the type of - :n:`@ident`. Tuples are decomposed in a width-first left-to-right order (for - instance if the type of :g:`H1` is :g:`A <-> B` and the type of - :g:`H2` is :g:`A` then ``apply H1 in H2`` transforms the type of :g:`H2` - into :g:`B`). The tactic ``apply`` relies on first-order pattern-matching + :token:`ident`. Tuples are decomposed in a width-first left-to-right order + (for instance if the type of :g:`H1` is :g:`A <-> B` and the type of + :g:`H2` is :g:`A` then :g:`apply H1 in H2` transforms the type of :g:`H2` + into :g:`B`). The tactic :tacn:`apply` relies on first-order pattern-matching with dependent types. -.. exn:: Statement without assumptions. - - This happens if the type of ``term`` has no non dependent premise. - -.. exn:: Unable to apply. + .. exn:: Statement without assumptions. - This happens if the conclusion of :n:`@ident` does not match any of the non - dependent premises of the type of ``term``. + This happens if the type of :token:`term` has no non-dependent premise. -.. tacv:: apply {+, @term} in @ident + .. exn:: Unable to apply. - This applies each of ``term`` in sequence in :n:`@ident`. + This happens if the conclusion of :token:`ident` does not match any of + the non-dependent premises of the type of :token:`term`. -.. tacv:: apply {+, @term with @bindings_list} in @ident + .. tacv:: apply {+, @term} in @ident - This does the same but uses the bindings in each :n:`(@id := @ val)` to - instantiate the parameters of the corresponding type of ``term`` (see - :ref:`bindings list <bindingslist>`). + This applies each :token:`term` in sequence in :token:`ident`. -.. tacv:: eapply {+, @term with @bindings_list} in @ident + .. tacv:: apply {+, @term with @bindings_list} in @ident - This works as :tacn:`apply ... in` but turns unresolved bindings into - existential variables, if any, instead of failing. + This does the same but uses the bindings in each :n:`(@ident := @term)` to + instantiate the parameters of the corresponding type of :token:`term` + (see :ref:`bindings list <bindingslist>`). -.. tacv:: apply {+, @term with @bindings_list} in @ident as @intro_pattern - :name: apply ... in ... as + .. tacv:: eapply {+, @term {? with @bindings_list } } in @ident - This works as :tacn:`apply ... in` then applies the - :n:`@intro_pattern` to the hypothesis :n:`@ident`. + This works as :tacn:`apply ... in` but turns unresolved bindings into + existential variables, if any, instead of failing. -.. tacv:: eapply {+, @term with @bindings_list} in @ident as @intro_pattern. + .. tacv:: apply {+, @term {? with @bindings_list } } in @ident as @intro_pattern + :name: apply ... in ... as - This works as :tacn:`apply ... in ... as` but using ``eapply``. + This works as :tacn:`apply ... in` then applies the :token:`intro_pattern` + to the hypothesis :token:`ident`. -.. tacv:: simple apply @term in @ident + .. tacv:: simple apply @term in @ident - This behaves like :tacn:`apply ... in` but it reasons modulo conversion only - on subterms that contain no variables to instantiate. For instance, if - :g:`id := fun x:nat => x` and :g:`H: forall y, id y = y -> True` and - :g:`H0 : O = O` then ``simple apply H in H0`` does not succeed because it - would require the conversion of :g:`id ?x` and :g:`O` where :g:`?x` is - an existential variable to instantiate. Tactic :n:`simple apply @term in @ident` does not - either traverse tuples as :n:`apply @term in @ident` does. + This behaves like :tacn:`apply ... in` but it reasons modulo conversion + only on subterms that contain no variables to instantiate. For instance, + if :g:`id := fun x:nat => x` and :g:`H: forall y, id y = y -> True` and + :g:`H0 : O = O` then :g:`simple apply H in H0` does not succeed because it + would require the conversion of :g:`id ?x` and :g:`O` where :g:`?x` is + an existential variable to instantiate. + Tactic :n:`simple apply @term in @ident` does not + either traverse tuples as :n:`apply @term in @ident` does. -.. tacv:: {? simple} apply {+, @term {? with @bindings_list}} in @ident {? as @intro_pattern} -.. tacv:: {? simple} eapply {+, @term {? with @bindings_list}} in @ident {? as @intro_pattern} + .. tacv:: {? simple} apply {+, @term {? with @bindings_list}} in @ident {? as @intro_pattern} + {? simple} eapply {+, @term {? with @bindings_list}} in @ident {? as @intro_pattern} - This summarizes the different syntactic variants of :n:`apply @term in @ident` - and :n:`eapply @term in @ident`. + This summarizes the different syntactic variants of :n:`apply @term in @ident` + and :n:`eapply @term in @ident`. .. tacn:: constructor @num :name: constructor This tactic applies to a goal such that its conclusion is an inductive - type (say :g:`I`). The argument :n:`@num` must be less or equal to the - numbers of constructor(s) of :g:`I`. Let :g:`c`:sub:`i` be the i-th - constructor of :g:`I`, then ``constructor i`` is equivalent to - ``intros; apply c``:sub:`i`. + type (say :g:`I`). The argument :token:`num` must be less or equal to the + numbers of constructor(s) of :g:`I`. Let :n:`c__i` be the i-th + constructor of :g:`I`, then :g:`constructor i` is equivalent to + :n:`intros; apply c__i`. -.. exn:: Not an inductive product. -.. exn:: Not enough constructors. - -.. tacv:: constructor - - This tries :g:`constructor`:sub:`1` then :g:`constructor`:sub:`2`, ..., then - :g:`constructor`:sub:`n` where `n` is the number of constructors of the head - of the goal. - -.. tacv:: constructor @num with @bindings_list - - Let ``c`` be the i-th constructor of :g:`I`, then - :n:`constructor i with @bindings_list` is equivalent to - :n:`intros; apply c with @bindings_list`. + .. exn:: Not an inductive product. + :undocumented: - .. warn:: - The terms in the @bindings_list are checked in the context where constructor is executed and not in the context where @apply is executed (the introductions are not taken into account). + .. exn:: Not enough constructors. + :undocumented: -.. tacv:: split - :name: split + .. tacv:: constructor - This applies only if :g:`I` has a single constructor. It is then - equivalent to :n:`constructor 1.`. It is typically used in the case of a - conjunction :g:`A` :math:`\wedge` :g:`B`. + This tries :g:`constructor 1` then :g:`constructor 2`, ..., then + :g:`constructor n` where ``n`` is the number of constructors of the head + of the goal. -.. exn:: Not an inductive goal with 1 constructor + .. tacv:: constructor @num with @bindings_list -.. tacv:: exists @val - :name: exists + Let ``c`` be the i-th constructor of :g:`I`, then + :n:`constructor i with @bindings_list` is equivalent to + :n:`intros; apply c with @bindings_list`. - This applies only if :g:`I` has a single constructor. It is then equivalent - to :n:`intros; constructor 1 with @bindings_list.` It is typically used in - the case of an existential quantification :math:`\exists`:g:`x, P(x).` - -.. exn:: Not an inductive goal with 1 constructor. - -.. tacv:: exists @bindings_list + .. warning:: - This iteratively applies :n:`exists @bindings_list`. + The terms in the :token:`bindings_list` are checked in the context + where constructor is executed and not in the context where :tacn:`apply` + is executed (the introductions are not taken into account). -.. tacv:: left - :name: left + .. tacv:: split {? with @bindings_list } + :name: split -.. tacv:: right - :name: right + This applies only if :g:`I` has a single constructor. It is then + equivalent to :n:`constructor 1 {? with @bindings_list }`. It is + typically used in the case of a conjunction :math:`A \wedge B`. - These tactics apply only if :g:`I` has two constructors, for - instance in the case of a disjunction :g:`A` :math:`\vee` :g:`B`. - Then, they are respectively equivalent to ``constructor 1`` and - ``constructor 2``. + .. tacv:: exists @bindings_list + :name: exists -.. exn:: Not an inductive goal with 2 constructors. + This applies only if :g:`I` has a single constructor. It is then equivalent + to :n:`intros; constructor 1 with @bindings_list.` It is typically used in + the case of an existential quantification :math:`\exists x, P(x).` -.. tacv:: left with @bindings_list -.. tacv:: right with @bindings_list -.. tacv:: split with @bindings_list + .. tacv:: exists {+, @bindings_list } - As soon as the inductive type has the right number of constructors, these - expressions are equivalent to calling :n:`constructor i with @bindings_list` - for the appropriate ``i``. + This iteratively applies :n:`exists @bindings_list`. -.. tacv:: econstructor - :name: econstructor + .. exn:: Not an inductive goal with 1 constructor. + :undocumented: -.. tacv:: eexists - :name: eexists + .. tacv:: left {? with @bindings_list } + right {? with @bindings_list } + :name: left; right -.. tacv:: esplit - :name: esplit + These tactics apply only if :g:`I` has two constructors, for + instance in the case of a disjunction :math:`A \vee B`. + Then, they are respectively equivalent to + :n:`constructor 1 {? with @bindings_list }` and + :n:`constructor 2 {? with @bindings_list }`. -.. tacv:: eleft - :name: eleft + .. exn:: Not an inductive goal with 2 constructors. -.. tacv:: eright - :name: eright + .. tacv:: econstructor + eexists + esplit + eleft + eright + :name: econstructor; eexists; esplit; eleft; eright - These tactics and their variants behave like :tacn:`constructor`, - :tacn:`exists`, :tacn:`split`, :tacn:`left`, :tacn:`right` and their variants - but they introduce existential variables instead of failing when the - instantiation of a variable cannot be found (cf. :tacn:`eapply` and - :tacn:`apply`). + These tactics and their variants behave like :tacn:`constructor`, + :tacn:`exists`, :tacn:`split`, :tacn:`left`, :tacn:`right` and their + variants but they introduce existential variables instead of failing + when the instantiation of a variable cannot be found + (cf. :tacn:`eapply` and :tacn:`apply`). .. _managingthelocalcontext: @@ -621,101 +614,107 @@ Managing the local context .. tacn:: intro :name: intro -This tactic applies to a goal that is either a product or starts with a let -binder. If the goal is a product, the tactic implements the "Lam" rule given in -:ref:`Typing-rules` [1]_. If the goal starts with a let binder, then the -tactic implements a mix of the "Let" and "Conv". + This tactic applies to a goal that is either a product or starts with a + let-binder. If the goal is a product, the tactic implements the "Lam" rule + given in :ref:`Typing-rules` [1]_. If the goal starts with a let-binder, + then the tactic implements a mix of the "Let" and "Conv". -If the current goal is a dependent product :g:`forall x:T, U` (resp -:g:`let x:=t in U`) then ``intro`` puts :g:`x:T` (resp :g:`x:=t`) in the local -context. The new subgoal is :g:`U`. + If the current goal is a dependent product :g:`forall x:T, U` + (resp :g:`let x:=t in U`) then :tacn:`intro` puts :g:`x:T` (resp :g:`x:=t`) + in the local context. The new subgoal is :g:`U`. -If the goal is a non-dependent product :g:`T`:math:`\rightarrow`:g:`U`, then it -puts in the local context either :g:`Hn:T` (if :g:`T` is of type :g:`Set` or -:g:`Prop`) or :g:`Xn:T` (if the type of :g:`T` is :g:`Type`). The optional index -``n`` is such that ``Hn`` or ``Xn`` is a fresh identifier. In both cases, the -new subgoal is :g:`U`. + If the goal is a non-dependent product :math:`T \rightarrow U`, then it + puts in the local context either :g:`Hn:T` (if :g:`T` is of type :g:`Set` + or :g:`Prop`) or :g:`Xn:T` (if the type of :g:`T` is :g:`Type`). + The optional index ``n`` is such that ``Hn`` or ``Xn`` is a fresh + identifier. In both cases, the new subgoal is :g:`U`. -If the goal is an existential variable, ``intro`` forces the resolution of the -existential variable into a dependent product :math:`forall`:g:`x:?X, ?Y`, puts -:g:`x:?X` in the local context and leaves :g:`?Y` as a new subgoal allowed to -depend on :g:`x`. + If the goal is an existential variable, :tacn:`intro` forces the resolution + of the existential variable into a dependent product :math:`\forall`\ :g:`x:?X, ?Y`, + puts :g:`x:?X` in the local context and leaves :g:`?Y` as a new subgoal + allowed to depend on :g:`x`. -the tactic ``intro`` applies the tactic ``hnf`` until the tactic ``intro`` can -be applied or the goal is not head-reducible. + The tactic :tacn:`intro` applies the tactic :tacn:`hnf` + until :tacn:`intro` can be applied or the goal is not head-reducible. -.. exn:: No product even after head-reduction. -.. exn:: @ident is already used. + .. exn:: No product even after head-reduction. + :undocumented: -.. tacv:: intros - :name: intros + .. tacv:: intro @ident - This repeats ``intro`` until it meets the head-constant. It never - reduces head-constants and it never fails. + This applies :tacn:`intro` but forces :token:`ident` to be the name of + the introduced hypothesis. -.. tacn:: intro @ident + .. exn:: @ident is already used. + :undocumented: - This applies ``intro`` but forces :n:`@ident` to be the name of the - introduced hypothesis. + .. note:: -.. exn:: Name @ident is already used. + If a name used by intro hides the base name of a global constant then + the latter can still be referred to by a qualified name + (see :ref:`Qualified-names`). -.. note:: If a name used by intro hides the base name of a global - constant then the latter can still be referred to by a qualified name - (see :ref:`Qualified-names`). -.. tacv:: intros {+ @ident}. + .. tacv:: intros + :name: intros - This is equivalent to the composed tactic - :n:`intro @ident; ... ; intro @ident`. More generally, the ``intros`` tactic - takes a pattern as argument in order to introduce names for components - of an inductive definition or to clear introduced hypotheses. This is - explained in :ref:`Managingthelocalcontext`. + This repeats :tacn:`intro` until it meets the head-constant. It never + reduces head-constants and it never fails. -.. tacv:: intros until @ident + .. tacv:: intros {+ @ident}. - This repeats intro until it meets a premise of the goal having form - `(@ident:term)` and discharges the variable named `ident` of the current - goal. + This is equivalent to the composed tactic :n:`intro @ident; ... ; intro @ident`. -.. exn:: No such hypothesis in current goal. + .. tacv:: intros until @ident -.. tacv:: intros until @num + This repeats intro until it meets a premise of the goal having the + form :n:`(@ident : @type)` and discharges the variable + named :token:`ident` of the current goal. - This repeats intro until the `num`-th non-dependent product. For instance, - on the subgoal :g:`forall x y:nat, x=y -> y=x` the tactic - :n:`intros until 1` is equivalent to :n:`intros x y H`, as :g:`x=y -> y=x` - is the first non-dependent product. And on the subgoal :g:`forall x y - z:nat, x=y -> y=x` the tactic :n:`intros until 1` is equivalent to - :n:`intros x y z` as the product on :g:`z` can be rewritten as a - non-dependent product: :g:`forall x y:nat, nat -> x=y -> y=x` + .. exn:: No such hypothesis in current goal. + :undocumented: -.. exn:: No such hypothesis in current goal. + .. tacv:: intros until @num - This happens when `num` is 0 or is greater than the number of non-dependent - products of the goal. + This repeats :tacn:`intro` until the :token:`num`\-th non-dependent + product. -.. tacv:: intro after @ident -.. tacv:: intro before @ident -.. tacv:: intro at top -.. tacv:: intro at bottom + .. example:: - These tactics apply :n:`intro` and move the freshly introduced hypothesis - respectively after the hypothesis :n:`@ident`, before the hypothesis - :n:`@ident`, at the top of the local context, or at the bottom of the local - context. All hypotheses on which the new hypothesis depends are moved - too so as to respect the order of dependencies between hypotheses. - Note that :n:`intro at bottom` is a synonym for :n:`intro` with no argument. + On the subgoal :g:`forall x y : nat, x = y -> y = x` the + tactic :n:`intros until 1` is equivalent to :n:`intros x y H`, + as :g:`x = y -> y = x` is the first non-dependent product. -.. exn:: No such hypothesis: @ident. + On the subgoal :g:`forall x y z : nat, x = y -> y = x` the + tactic :n:`intros until 1` is equivalent to :n:`intros x y z` + as the product on :g:`z` can be rewritten as a non-dependent + product: :g:`forall x y : nat, nat -> x = y -> y = x`. + + .. exn:: No such hypothesis in current goal. + + This happens when :token:`num` is 0 or is greater than the number of + non-dependent products of the goal. + + .. tacv:: intro {? @ident__1 } after @ident__2 + intro {? @ident__1 } before @ident__2 + intro {? @ident__1 } at top + intro {? @ident__1 } at bottom -.. tacv:: intro @ident after @ident -.. tacv:: intro @ident before @ident -.. tacv:: intro @ident at top -.. tacv:: intro @ident at bottom + These tactics apply :n:`intro {? @ident__1}` and move the freshly + introduced hypothesis respectively after the hypothesis :n:`@ident__2`, + before the hypothesis :n:`@ident__2`, at the top of the local context, + or at the bottom of the local context. All hypotheses on which the new + hypothesis depends are moved too so as to respect the order of + dependencies between hypotheses. It is equivalent to :n:`intro {? @ident__1 }` + followed by the appropriate call to :tacn:`move ... after ...`, + :tacn:`move ... before ...`, :tacn:`move ... at top`, + or :tacn:`move ... at bottom`. - These tactics behave as previously but naming the introduced hypothesis - :n:`@ident`. It is equivalent to :n:`intro @ident` followed by the - appropriate call to ``move`` (see :tacn:`move ... after ...`). + .. note:: + + :n:`intro at bottom` is a synonym for :n:`intro` with no argument. + + .. exn:: No such hypothesis: @ident. + :undocumented: .. tacn:: intros @intro_pattern_list :name: intros ... @@ -764,24 +763,22 @@ be applied or the goal is not head-reducible. :n:`intros p` is defined inductively over the structure of the introduction pattern :n:`p`: -Introduction on :n:`?` performs the introduction, and lets Coq choose a fresh -name for the variable; - -Introduction on :n:`?ident` performs the introduction, and lets Coq choose a -fresh name for the variable based on :n:`@ident`; + Introduction on :n:`?` performs the introduction, and lets Coq choose a fresh + name for the variable; -Introduction on :n:`@ident` behaves as described in :tacn:`intro` + Introduction on :n:`?@ident` performs the introduction, and lets Coq choose a + fresh name for the variable based on :n:`@ident`; -Introduction over a disjunction of list of patterns -:n:`[@intro_pattern_list | ... | @intro_pattern_list ]` expects the product -to be over an inductive type whose number of constructors is `n` (or more -generally over a type of conclusion an inductive type built from `n` -constructors, e.g. :g:`C -> A\/B` with `n=2` since :g:`A\/B` has `2` -constructors): it destructs the introduced hypothesis as :n:`destruct` (see -:tacn:`destruct`) would and applies on each generated subgoal the -corresponding tactic; + Introduction on :n:`@ident` behaves as described in :tacn:`intro` -.. tacv:: intros @intro_pattern_list + Introduction over a disjunction of list of patterns + :n:`[@intro_pattern_list | ... | @intro_pattern_list ]` expects the product + to be over an inductive type whose number of constructors is `n` (or more + generally over a type of conclusion an inductive type built from `n` + constructors, e.g. :g:`C -> A\/B` with `n=2` since :g:`A\/B` has `2` + constructors): it destructs the introduced hypothesis as :n:`destruct` (see + :tacn:`destruct`) would and applies on each generated subgoal the + corresponding tactic; The introduction patterns in :n:`@intro_pattern_list` are expected to consume no more than the number of arguments of the `i`-th constructor. If it @@ -790,59 +787,59 @@ corresponding tactic; list of patterns :n:`[ | ] H` applied on goal :g:`forall x:nat, x=0 -> 0=x` behaves the same as the list of patterns :n:`[ | ? ] H`); -Introduction over a conjunction of patterns :n:`({+, p})` expects -the goal to be a product over an inductive type :g:`I` with a single -constructor that itself has at least `n` arguments: It performs a case -analysis over the hypothesis, as :n:`destruct` would, and applies the -patterns :n:`{+ p}` to the arguments of the constructor of :g:`I` (observe -that :n:`({+ p})` is an alternative notation for :n:`[{+ p}]`); - -Introduction via :n:`({+& p})` is a shortcut for introduction via -:n:`(p,( ... ,( ..., p ) ... ))`; it expects the hypothesis to be a sequence of -right-associative binary inductive constructors such as :g:`conj` or -:g:`ex_intro`; for instance, an hypothesis with type -:g:`A /\(exists x, B /\ C /\ D)` can be introduced via pattern -:n:`(a & x & b & c & d)`; - -If the product is over an equality type, then a pattern of the form -:n:`[= {+ p}]` applies either :tacn:`injection` or :tacn:`discriminate` -instead of :tacn:`destruct`; if :tacn:`injection` is applicable, the patterns -:n:`{+, p}` are used on the hypotheses generated by :tacn:`injection`; if the -number of patterns is smaller than the number of hypotheses generated, the -pattern :n:`?` is used to complete the list; - -.. tacv:: introduction over -> -.. tacv:: introduction over <- - + Introduction over a conjunction of patterns :n:`({+, p})` expects + the goal to be a product over an inductive type :g:`I` with a single + constructor that itself has at least `n` arguments: It performs a case + analysis over the hypothesis, as :n:`destruct` would, and applies the + patterns :n:`{+ p}` to the arguments of the constructor of :g:`I` (observe + that :n:`({+ p})` is an alternative notation for :n:`[{+ p}]`); + + Introduction via :n:`({+& p})` is a shortcut for introduction via + :n:`(p,( ... ,( ..., p ) ... ))`; it expects the hypothesis to be a sequence of + right-associative binary inductive constructors such as :g:`conj` or + :g:`ex_intro`; for instance, a hypothesis with type + :g:`A /\(exists x, B /\ C /\ D)` can be introduced via pattern + :n:`(a & x & b & c & d)`; + + If the product is over an equality type, then a pattern of the form + :n:`[= {+ p}]` applies either :tacn:`injection` or :tacn:`discriminate` + instead of :tacn:`destruct`; if :tacn:`injection` is applicable, the patterns + :n:`{+, p}` are used on the hypotheses generated by :tacn:`injection`; if the + number of patterns is smaller than the number of hypotheses generated, the + pattern :n:`?` is used to complete the list. + + Introduction over ``->`` (respectively over ``<-``) expects the hypothesis to be an equality and the right-hand-side (respectively the left-hand-side) is replaced by the left-hand-side (respectively the right-hand-side) in the conclusion of the goal; the hypothesis itself is erased; if the term to substitute is a variable, it - is substituted also in the context of goal and the variable is removed too; + is substituted also in the context of goal and the variable is removed too. -Introduction over a pattern :n:`p{+ %term}` first applies :n:`{+ term}` -on the hypothesis to be introduced (as in :n:`apply {+, term}`) prior to the -application of the introduction pattern :n:`p`; + Introduction over a pattern :n:`p{+ %term}` first applies :n:`{+ term}` + on the hypothesis to be introduced (as in :n:`apply {+, term}`) prior to the + application of the introduction pattern :n:`p`; -Introduction on the wildcard depends on whether the product is dependent or not: -in the non-dependent case, it erases the corresponding hypothesis (i.e. it -behaves as an :tacn:`intro` followed by a :tacn:`clear`) while in the -dependent case, it succeeds and erases the variable only if the wildcard is part -of a more complex list of introduction patterns that also erases the hypotheses -depending on this variable; + Introduction on the wildcard depends on whether the product is dependent or not: + in the non-dependent case, it erases the corresponding hypothesis (i.e. it + behaves as an :tacn:`intro` followed by a :tacn:`clear`) while in the + dependent case, it succeeds and erases the variable only if the wildcard is part + of a more complex list of introduction patterns that also erases the hypotheses + depending on this variable; -Introduction over :n:`*` introduces all forthcoming quantified variables -appearing in a row; introduction over :n:`**` introduces all forthcoming -quantified variables or hypotheses until the goal is not any more a -quantification or an implication. + Introduction over :n:`*` introduces all forthcoming quantified variables + appearing in a row; introduction over :n:`**` introduces all forthcoming + quantified variables or hypotheses until the goal is not any more a + quantification or an implication. -.. example:: - .. coqtop:: all + .. example:: - Goal forall A B C:Prop, A \/ B /\ C -> (A -> C) -> C. - intros * [a | (_,c)] f. + .. coqtop:: reset all + + Goal forall A B C:Prop, A \/ B /\ C -> (A -> C) -> C. + intros * [a | (_,c)] f. .. note:: + :n:`intros {+ p}` is not equivalent to :n:`intros p; ... ; intros p` for the following reason: If one of the :n:`p` is a wildcard pattern, it might succeed in the first case because the further hypotheses it @@ -851,6 +848,7 @@ quantification or an implication. introduced (and a fortiori not yet erased). .. note:: + In :n:`intros @intro_pattern_list`, if the last introduction pattern is a disjunctive or conjunctive pattern :n:`[{+| @intro_pattern_list}]`, the completion of :n:`@intro_pattern_list` @@ -869,38 +867,42 @@ quantification or an implication. the current goal. As a consequence, :n:`@ident` is no more displayed and no more usable in the proof development. -.. exn:: No such hypothesis. + .. exn:: No such hypothesis. + :undocumented: -.. exn:: @ident is used in the conclusion. + .. exn:: @ident is used in the conclusion. + :undocumented: -.. exn:: @ident is used in the hypothesis @ident. + .. exn:: @ident is used in the hypothesis @ident. + :undocumented: -.. tacv:: clear {+ @ident} + .. tacv:: clear {+ @ident} - This is equivalent to :n:`clear @ident. ... clear @ident.` + This is equivalent to :n:`clear @ident. ... clear @ident.` -.. tacv:: clear - {+ @ident} + .. tacv:: clear - {+ @ident} - This tactic clears all the hypotheses except the ones depending in the - hypotheses named :n:`{+ @ident}` and in the goal. + This variant clears all the hypotheses except the ones depending in the + hypotheses named :n:`{+ @ident}` and in the goal. -.. tacv:: clear + .. tacv:: clear - This tactic clears all the hypotheses except the ones the goal depends on. + This variants clears all the hypotheses except the ones the goal depends on. -.. tacv:: clear dependent @ident + .. tacv:: clear dependent @ident - This clears the hypothesis :n:`@ident` and all the hypotheses that depend on - it. + This clears the hypothesis :token:`ident` and all the hypotheses that + depend on it. -.. tacv:: clearbody {+ @ident} - :name: clearbody + .. tacv:: clearbody {+ @ident} + :name: clearbody - This tactic expects :n:`{+ @ident}` to be local definitions and clears their - respective bodies. - In other words, it turns the given definitions into assumptions. + This tactic expects :n:`{+ @ident}` to be local definitions and clears + their respective bodies. + In other words, it turns the given definitions into assumptions. -.. exn:: @ident is not a local definition. + .. exn:: @ident is not a local definition. + :undocumented: .. tacn:: revert {+ @ident} :name: revert @@ -909,171 +911,184 @@ quantification or an implication. (possibly defined) to the goal, if this respects dependencies. This tactic is the inverse of :tacn:`intro`. -.. exn:: No such hypothesis. + .. exn:: No such hypothesis. + :undocumented: -.. exn:: @ident is used in the hypothesis @ident. + .. exn:: @ident__1 is used in the hypothesis @ident__2. + :undocumented: -.. tacn:: revert dependent @ident + .. tacv:: revert dependent @ident + :name: revert dependent - This moves to the goal the hypothesis :n:`@ident` and all the hypotheses that - depend on it. + This moves to the goal the hypothesis :token:`ident` and all the + hypotheses that depend on it. -.. tacn:: move @ident after @ident +.. tacn:: move @ident__1 after @ident__2 :name: move ... after ... - This moves the hypothesis named :n:`@ident` in the local context after the - hypothesis named :n:`@ident`, where “after” is in reference to the + This moves the hypothesis named :n:`@ident__1` in the local context after + the hypothesis named :n:`@ident__2`, where “after” is in reference to the direction of the move. The proof term is not changed. - If :n:`@ident` comes before :n:`@ident` in the order of dependencies, then - all the hypotheses between :n:`@ident` and :n:`ident@` that (possibly - indirectly) depend on :n:`@ident` are moved too, and all of them are thus - moved after :n:`@ident` in the order of dependencies. + If :n:`@ident__1` comes before :n:`@ident__2` in the order of dependencies, + then all the hypotheses between :n:`@ident__1` and :n:`@ident__2` that + (possibly indirectly) depend on :n:`@ident__1` are moved too, and all of + them are thus moved after :n:`@ident__2` in the order of dependencies. - If :n:`@ident` comes after :n:`@ident` in the order of dependencies, then all - the hypotheses between :n:`@ident` and :n:`@ident` that (possibly indirectly) - occur in the type of :n:`@ident` are moved too, and all of them are thus - moved before :n:`@ident` in the order of dependencies. + If :n:`@ident__1` comes after :n:`@ident__2` in the order of dependencies, + then all the hypotheses between :n:`@ident__1` and :n:`@ident__2` that + (possibly indirectly) occur in the type of :n:`@ident__1` are moved too, + and all of them are thus moved before :n:`@ident__2` in the order of + dependencies. -.. tacv:: move @ident before @ident + .. tacv:: move @ident__1 before @ident__2 + :name: move ... before ... - This moves :n:`@ident` towards and just before the hypothesis named - :n:`@ident`. As for :tacn:`move ... after ...`, dependencies over - :n:`@ident` (when :n:`@ident` comes before :n:`@ident` in the order of - dependencies) or in the type of :n:`@ident` (when :n:`@ident` comes after - :n:`@ident` in the order of dependencies) are moved too. + This moves :n:`@ident__1` towards and just before the hypothesis + named :n:`@ident__2`. As for :tacn:`move ... after ...`, dependencies + over :n:`@ident__1` (when :n:`@ident__1` comes before :n:`@ident__2` in + the order of dependencies) or in the type of :n:`@ident__1` + (when :n:`@ident__1` comes after :n:`@ident__2` in the order of + dependencies) are moved too. -.. tacv:: move @ident at top + .. tacv:: move @ident at top + :name: move ... at top - This moves :n:`@ident` at the top of the local context (at the beginning of - the context). + This moves :token:`ident` at the top of the local context (at the beginning + of the context). -.. tacv:: move @ident at bottom + .. tacv:: move @ident at bottom + :name: move ... at bottom - This moves ident at the bottom of the local context (at the end of the - context). + This moves :token:`ident` at the bottom of the local context (at the end of + the context). -.. exn:: No such hypothesis. -.. exn:: Cannot move @ident after @ident : it occurs in the type of @ident. -.. exn:: Cannot move @ident after @ident : it depends on @ident. + .. exn:: No such hypothesis. + :undocumented: -.. example:: - .. coqtop:: all + .. exn:: Cannot move @ident__1 after @ident__2: it occurs in the type of @ident__2. + :undocumented: + + .. exn:: Cannot move @ident__1 after @ident__2: it depends on @ident__2. + :undocumented: + + .. example:: + + .. coqtop:: reset all - Goal forall x :nat, x = 0 -> forall z y:nat, y=y-> 0=x. - intros x H z y H0. - move x after H0. - Undo. - move x before H0. - Undo. - move H0 after H. - Undo. - move H0 before H. - -.. tacn:: rename @ident into @ident + Goal forall x :nat, x = 0 -> forall z y:nat, y=y-> 0=x. + intros x H z y H0. + move x after H0. + Undo. + move x before H0. + Undo. + move H0 after H. + Undo. + move H0 before H. + +.. tacn:: rename @ident__1 into @ident__2 :name: rename -This renames hypothesis :n:`@ident` into :n:`@ident` in the current context. -The name of the hypothesis in the proof-term, however, is left unchanged. + This renames hypothesis :n:`@ident__1` into :n:`@ident__2` in the current + context. The name of the hypothesis in the proof-term, however, is left + unchanged. -.. tacv:: rename {+, @ident into @ident} + .. tacv:: rename {+, @ident__i into @ident__j} - This renames the variables :n:`@ident` into :n:`@ident` in parallel. In - particular, the target identifiers may contain identifiers that exist in the - source context, as long as the latter are also renamed by the same tactic. + This renames the variables :n:`@ident__i` into :n:`@ident__j` in parallel. + In particular, the target identifiers may contain identifiers that exist in + the source context, as long as the latter are also renamed by the same + tactic. -.. exn:: No such hypothesis. -.. exn:: @ident is already used. + .. exn:: No such hypothesis. + :undocumented: + + .. exn:: @ident is already used. + :undocumented: .. tacn:: set (@ident := @term) :name: set - This replaces :n:`@term` by :n:`@ident` in the conclusion of the current goal - and adds the new definition :g:`ident := term` to the local context. - - If :n:`@term` has holes (i.e. subexpressions of the form “`_`”), the tactic - first checks that all subterms matching the pattern are compatible before - doing the replacement using the leftmost subterm matching the pattern. + This replaces :token:`term` by :token:`ident` in the conclusion of the + current goal and adds the new definition :n:`@ident := @term` to the + local context. -.. exn:: The variable @ident is already defined. + If :token:`term` has holes (i.e. subexpressions of the form “`_`”), the + tactic first checks that all subterms matching the pattern are compatible + before doing the replacement using the leftmost subterm matching the + pattern. -.. tacv:: set (@ident := @term ) in @goal_occurrences + .. exn:: The variable @ident is already defined. + :undocumented: - This notation allows specifying which occurrences of :n:`@term` have to be - substituted in the context. The :n:`in @goal_occurrences` clause is an - occurrence clause whose syntax and behavior are described in - :ref:`goal occurences <occurencessets>`. + .. tacv:: set (@ident := @term) in @goal_occurrences -.. tacv:: set (@ident {+ @binder} := @term ) + This notation allows specifying which occurrences of :token:`term` have + to be substituted in the context. The :n:`in @goal_occurrences` clause + is an occurrence clause whose syntax and behavior are described in + :ref:`goal occurences <occurencessets>`. - This is equivalent to :n:`set (@ident := funbinder {+ binder} => @term )`. + .. tacv:: set (@ident @binders := @term) {? in @goal_occurrences } -.. tacv:: set term - This behaves as :n:`set(@ident := @term)` but :n:`@ident` is generated by - Coq. This variant also supports an occurrence clause. + This is equivalent to :n:`set (@ident := fun @binders => @term) {? in @goal_occurrences }`. -.. tacv:: set (@ident {+ @binder} := @term) in @goal_occurrences -.. tacv:: set @term in @goal_occurrences + .. tacv:: set @term {? in @goal_occurrences } - These are the general forms that combine the previous possibilities. + This behaves as :n:`set (@ident := @term) {? in @goal_occurrences }` + but :token:`ident` is generated by Coq. -.. tacv:: eset (@ident {+ @binder} := @term ) in @goal_occurrences -.. tacv:: eset @term in @goal_occurrences - :name: eset + .. tacv:: eset (@ident {? @binders } := @term) {? in @goal_occurrences } + eset @term {? in @goal_occurrences } + :name: eset; _ - While the different variants of :tacn:`set` expect that no existential - variables are generated by the tactic, :n:`eset` removes this constraint. In - practice, this is relevant only when :n:`eset` is used as a synonym of - :tacn:`epose`, i.e. when the :`@term` does not occur in the goal. + While the different variants of :tacn:`set` expect that no existential + variables are generated by the tactic, :tacn:`eset` removes this + constraint. In practice, this is relevant only when :tacn:`eset` is + used as a synonym of :tacn:`epose`, i.e. when the :token:`term` does + not occur in the goal. -.. tacv:: remember @term as @ident +.. tacn:: remember @term as @ident__1 {? eqn:@ident__2 } :name: remember - This behaves as :n:`set (@ident:= @term ) in *` and using a logical + This behaves as :n:`set (@ident__1 := @term) in *`, using a logical (Leibniz’s) equality instead of a local definition. + If :n:`@ident__2` is provided, it will be the name of the new equation. -.. tacv:: remember @term as @ident eqn:@ident - - This behaves as :n:`remember @term as @ident`, except that the name of the - generated equality is also given. - -.. tacv:: remember @term as @ident in @goal_occurrences + .. tacv:: remember @term as @ident__1 {? eqn:@ident__2 } in @goal_occurrences - This is a more general form of :n:`remember` that remembers the occurrences - of term specified by an occurrence set. + This is a more general form of :tacn:`remember` that remembers the + occurrences of :token:`term` specified by an occurrence set. -.. tacv:: eremember @term as @ident -.. tacv:: eremember @term as @ident in @goal_occurrences -.. tacv:: eremember @term as @ident eqn:@ident - :name: eremember + .. tacv:: eremember @term as @ident__1 {? eqn:@ident__2 } {? in @goal_occurrences } + :name: eremember - While the different variants of :n:`remember` expect that no existential - variables are generated by the tactic, :n:`eremember` removes this constraint. + While the different variants of :tacn:`remember` expect that no + existential variables are generated by the tactic, :tacn:`eremember` + removes this constraint. -.. tacv:: pose ( @ident := @term ) +.. tacn:: pose (@ident := @term) :name: pose This adds the local definition :n:`@ident := @term` to the current context without performing any replacement in the goal or in the hypotheses. It is - equivalent to :n:`set ( @ident := @term ) in |-`. + equivalent to :n:`set (@ident := @term) in |-`. -.. tacv:: pose ( @ident {+ @binder} := @term ) + .. tacv:: pose (@ident @binders := @term) - This is equivalent to :n:`pose (@ident := funbinder {+ binder} => @term)`. + This is equivalent to :n:`pose (@ident := fun @binders => @term)`. -.. tacv:: pose @term + .. tacv:: pose @term - This behaves as :n:`pose (@ident := @term )` but :n:`@ident` is generated by - Coq. + This behaves as :n:`pose (@ident := @term)` but :token:`ident` is + generated by Coq. -.. tacv:: epose (@ident := @term ) -.. tacv:: epose (@ident {+ @binder} := @term ) -.. tacv:: epose term - :name: epose + .. tacv:: epose (@ident {? @binders} := @term) + .. tacv:: epose term + :name: epose - While the different variants of :tacn:`pose` expect that no - existential variables are generated by the tactic, epose removes this - constraint. + While the different variants of :tacn:`pose` expect that no + existential variables are generated by the tactic, :tacn:`epose` + removes this constraint. .. tacn:: decompose [{+ @qualid}] @term :name: decompose @@ -1081,24 +1096,30 @@ The name of the hypothesis in the proof-term, however, is left unchanged. This tactic recursively decomposes a complex proposition in order to obtain atomic ones. -.. example:: - .. coqtop:: all + .. example:: - Goal forall A B C:Prop, A /\ B /\ C \/ B /\ C \/ C /\ A -> C. - intros A B C H; decompose [and or] H; assumption. - Qed. + .. coqtop:: reset all + + Goal forall A B C:Prop, A /\ B /\ C \/ B /\ C \/ C /\ A -> C. + intros A B C H; decompose [and or] H. + all: assumption. + Qed. -:n:`decompose` does not work on right-hand sides of implications or products. + .. note:: + + :tacn:`decompose` does not work on right-hand sides of implications or + products. + + .. tacv:: decompose sum @term -.. tacv:: decompose sum @term + This decomposes sum types (like :g:`or`). - This decomposes sum types (like or). + .. tacv:: decompose record @term -.. tacv:: decompose record @term + This decomposes record types (inductive types with one constructor, + like :g:`and` and :g:`exists` and those defined with the :cmd:`Record` + command. - This decomposes record types (inductive types with one constructor, like - "and" and "exists" and those defined with the Record macro, see - :ref:`record-types`). .. _controllingtheproofflow: @@ -1252,6 +1273,7 @@ Controlling the proof flow respect to some term. .. example:: + .. coqtop:: reset none Goal forall x y:nat, 0 <= x + y + y. @@ -1362,7 +1384,7 @@ goals cannot be closed with :g:`Qed` but only with :g:`Admitted`. :name: contradiction This tactic applies to any goal. The contradiction tactic attempts to - find in the current context (after all intros) an hypothesis that is + find in the current context (after all intros) a hypothesis that is equivalent to an empty inductive type (e.g. :g:`False`), to the negation of a singleton inductive type (e.g. :g:`True` or :g:`x=x`), or two contradictory hypotheses. @@ -1404,94 +1426,101 @@ analysis on inductive or co-inductive objects (see :ref:`inductive-definitions`) .. tacn:: destruct @term :name: destruct - This tactic applies to any goal. The argument :n:`@term` must be of + This tactic applies to any goal. The argument :token:`term` must be of inductive or co-inductive type and the tactic generates subgoals, one - for each possible form of :n:`@term`, i.e. one for each constructor of the - inductive or co-inductive type. Unlike :n:`induction`, no induction - hypothesis is generated by :n:`destruct`. + for each possible form of :token:`term`, i.e. one for each constructor of the + inductive or co-inductive type. Unlike :tacn:`induction`, no induction + hypothesis is generated by :tacn:`destruct`. - There are special cases: + .. tacv:: destruct @ident - + If :n:`@term` is an identifier :n:`@ident` denoting a quantified variable - of the conclusion of the goal, then :n:`destruct @ident` behaves as - :n:`intros until @ident; destruct @ident`. If :n:`@ident` is not anymore - dependent in the goal after application of :n:`destruct`, it is erased - (to avoid erasure, use parentheses, as in :n:`destruct (@ident)`). + If :token:`ident` denotes a quantified variable of the conclusion + of the goal, then :n:`destruct @ident` behaves + as :n:`intros until @ident; destruct @ident`. If :token:`ident` is not + anymore dependent in the goal after application of :tacn:`destruct`, it + is erased (to avoid erasure, use parentheses, as in :n:`destruct (@ident)`). - + If term is a num, then destruct num behaves as intros until num - followed by destruct applied to the last introduced hypothesis. + If :token:`ident` is a hypothesis of the context, and :token:`ident` + is not anymore dependent in the goal after application + of :tacn:`destruct`, it is erased (to avoid erasure, use parentheses, as + in :n:`destruct (@ident)`). + + .. tacv:: destruct @num + + :n:`destruct @num` behaves as :n:`intros until @num` + followed by destruct applied to the last introduced hypothesis. .. note:: - For destruction of a numeral, use syntax destruct (num) (not + For destruction of a numeral, use syntax :n:`destruct (@num)` (not very interesting anyway). - + In case term is an hypothesis :n:`@ident` of the context, and :n:`@ident` - is not anymore dependent in the goal after application of :n:`destruct`, it - is erased (to avoid erasure, use parentheses, as in :n:`destruct (@ident)`). + .. tacv:: destruct @pattern - + The argument :n:`@term` can also be a pattern of which holes are denoted - by “_”. In this case, the tactic checks that all subterms matching the - pattern in the conclusion and the hypotheses are compatible and - performs case analysis using this subterm. + The argument of :tacn:`destruct` can also be a pattern of which holes are + denoted by “_”. In this case, the tactic checks that all subterms + matching the pattern in the conclusion and the hypotheses are compatible + and performs case analysis using this subterm. -.. tacv:: destruct {+, @term} + .. tacv:: destruct {+, @term} - This is a shortcut for :n:`destruct term; ...; destruct term`. + This is a shortcut for :n:`destruct @term; ...; destruct @term`. -.. tacv:: destruct @term as @disj_conj_intro_pattern + .. tacv:: destruct @term as @disj_conj_intro_pattern - This behaves as :n:`destruct @term` but uses the names in :n:`@intro_pattern` - to name the variables introduced in the context. The :n:`@intro_pattern` must - have the form :n:`[p11 ... p1n | ... | pm1 ... pmn ]` with `m` being the - number of constructors of the type of :n:`@term`. Each variable introduced - by :n:`destruct` in the context of the `i`-th goal gets its name from the - list :n:`pi1 ... pin` in order. If there are not enough names, - :n:`@destruct` invents names for the remaining variables to introduce. More - generally, the :n:`pij` can be any introduction pattern (see - :tacn:`intros`). This provides a concise notation for chaining destruction of - an hypothesis. + This behaves as :n:`destruct @term` but uses the names + in :token:`disj_conj_intro_pattern` to name the variables introduced in the + context. The :token:`disj_conj_intro_pattern` must have the + form :n:`[p11 ... p1n | ... | pm1 ... pmn ]` with ``m`` being the + number of constructors of the type of :token:`term`. Each variable + introduced by :tacn:`destruct` in the context of the ``i``-th goal + gets its name from the list :n:`pi1 ... pin` in order. If there are not + enough names, :tacn:`destruct` invents names for the remaining variables + to introduce. More generally, the :n:`pij` can be any introduction + pattern (see :tacn:`intros`). This provides a concise notation for + chaining destruction of a hypothesis. -.. tacv:: destruct @term eqn:@naming_intro_pattern + .. tacv:: destruct @term eqn:@naming_intro_pattern + :name: destruct ... eqn: - This behaves as :n:`destruct @term` but adds an equation between :n:`@term` - and the value that :n:`@term` takes in each of the possible cases. The name - of the equation is specified by :n:`@naming_intro_pattern` (see - :tacn:`intros`), in particular `?` can be used to let Coq generate a fresh - name. + This behaves as :n:`destruct @term` but adds an equation + between :token:`term` and the value that it takes in each of the + possible cases. The name of the equation is specified + by :token:`naming_intro_pattern` (see :tacn:`intros`), + in particular ``?`` can be used to let Coq generate a fresh name. -.. tacv:: destruct @term with @bindings_list + .. tacv:: destruct @term with @bindings_list - This behaves like :n:`destruct @term` providing explicit instances for the - dependent premises of the type of :n:`@term` (see :ref:`syntax of bindings <bindingslist>`). + This behaves like :n:`destruct @term` providing explicit instances for + the dependent premises of the type of :token:`term`. -.. tacv:: edestruct @term - :name: edestruct + .. tacv:: edestruct @term + :name: edestruct - This tactic behaves like :n:`destruct @term` except that it does not fail if - the instance of a dependent premises of the type of :n:`@term` is not - inferable. Instead, the unresolved instances are left as existential - variables to be inferred later, in the same way as :tacn:`eapply` does. + This tactic behaves like :n:`destruct @term` except that it does not + fail if the instance of a dependent premises of the type + of :token:`term` is not inferable. Instead, the unresolved instances + are left as existential variables to be inferred later, in the same way + as :tacn:`eapply` does. -.. tacv:: destruct @term using @term -.. tacv:: destruct @term using @term with @bindings_list + .. tacv:: destruct @term using @term {? with @bindings_list } - These are synonyms of :n:`induction @term using @term` and - :n:`induction @term using @term with @bindings_list`. + This is synonym of :n:`induction @term using @term {? with @bindings_list }`. -.. tacv:: destruct @term in @goal_occurrences + .. tacv:: destruct @term in @goal_occurrences - This syntax is used for selecting which occurrences of :n:`@term` the case - analysis has to be done on. The :n:`in @goal_occurrences` clause is an - occurrence clause whose syntax and behavior is described in - :ref:`occurences sets <occurencessets>`. + This syntax is used for selecting which occurrences of :token:`term` + the case analysis has to be done on. The :n:`in @goal_occurrences` + clause is an occurrence clause whose syntax and behavior is described + in :ref:`occurences sets <occurencessets>`. -.. tacv:: destruct @term with @bindings_list as @disj_conj_intro_pattern eqn:@naming_intro_pattern using @term with @bindings_list in @goal_occurrences -.. tacv:: edestruct @term with @bindings_list as @disj_conj_intro_pattern eqn:@naming_intro_pattern using @term with @bindings_list in @goal_occurrences + .. tacv:: destruct @term {? with @bindings_list } {? as @disj_conj_intro_pattern } {? eqn:@naming_intro_pattern } {? using @term {? with @bindings_list } } {? in @goal_occurrences } + edestruct @term {? with @bindings_list } {? as @disj_conj_intro_pattern } {? eqn:@naming_intro_pattern } {? using @term {? with @bindings_list } } {? in @goal_occurrences } - These are the general forms of :n:`destruct` and :n:`edestruct`. They combine - the effects of the `with`, `as`, `eqn:`, `using`, and `in` clauses. + These are the general forms of :tacn:`destruct` and :tacn:`edestruct`. + They combine the effects of the ``with``, ``as``, ``eqn:``, ``using``, + and ``in`` clauses. -.. tacv:: case term +.. tacn:: case term :name: case The tactic :n:`case` is a more basic tactic to perform case analysis without @@ -1557,7 +1586,7 @@ analysis on inductive or co-inductive objects (see :ref:`inductive-definitions`) For simple induction on a numeral, use syntax induction (num) (not very interesting anyway). - + In case term is an hypothesis :n:`@ident` of the context, and :n:`@ident` + + In case term is a hypothesis :n:`@ident` of the context, and :n:`@ident` is not anymore dependent in the goal after application of :n:`induction`, it is erased (to avoid erasure, use parentheses, as in :n:`induction (@ident)`). @@ -1567,6 +1596,7 @@ analysis on inductive or co-inductive objects (see :ref:`inductive-definitions`) performs induction using this subterm. .. example:: + .. coqtop:: reset all Lemma induction_test : forall n:nat, n = n -> n <= n. @@ -1636,6 +1666,7 @@ analysis on inductive or co-inductive objects (see :ref:`inductive-definitions`) those are generalized as well in the statement to prove. .. example:: + .. coqtop:: reset all Lemma comm x y : x + y = y + x. @@ -1744,6 +1775,7 @@ analysis on inductive or co-inductive objects (see :ref:`inductive-definitions`) still get enough information in the proofs. .. example:: + .. coqtop:: reset all Lemma le_minus : forall n:nat, n < 1 -> n = 0. @@ -1809,6 +1841,7 @@ and an explanation of the underlying technique. Note that this tactic is only available after a ``Require Import FunInd``. .. example:: + .. coqtop:: reset all Require Import FunInd. @@ -1845,9 +1878,7 @@ and an explanation of the underlying technique. :g:`Fixpoint` or :g:`Definition`. See :ref:`advanced-recursive-functions` for details. -See also: :ref:`advanced-recursive-functions` - :ref:`functional-scheme` - :tacn:`inversion` +.. seealso:: :ref:`advanced-recursive-functions`, :ref:`functional-scheme` and :tacn:`inversion` .. exn:: Cannot find induction information on @qualid. .. exn:: Not the right number of induction arguments. @@ -2008,7 +2039,7 @@ See also: :ref:`advanced-recursive-functions` the number of equalities newly generated. If it is smaller, fresh names are automatically generated to adjust the list of :n:`@intro_pattern` to the number of new equalities. The original equality is erased if it - corresponds to an hypothesis. + corresponds to a hypothesis. .. opt:: Structural Injection @@ -2279,8 +2310,8 @@ See also: :ref:`advanced-recursive-functions` As H occurs in the goal, we may want to reason by cases on its structure and so, we would like inversion tactics to substitute H by - the corresponding @term in constructor form. Neither Inversion nor - Inversion_clear make such a substitution. To have such a behavior we + the corresponding @term in constructor form. Neither :tacn:`inversion` nor + :n:`inversion_clear` do such a substitution. To have such a behavior we use the dependent inversion tactics: .. coqtop:: all @@ -2856,6 +2887,7 @@ the conversion in hypotheses :n:`{+ @ident}`. + A constant can be marked to be never unfolded by ``cbn`` or ``simpl``: .. example:: + .. coqtop:: all Arguments minus n m : simpl never. @@ -2868,6 +2900,7 @@ the conversion in hypotheses :n:`{+ @ident}`. ``/`` symbol in the argument list of the :cmd:`Arguments` vernacular command. .. example:: + .. coqtop:: all Definition fcomp A B C f (g : A -> B) (x : A) : C := f (g x). @@ -2880,6 +2913,7 @@ the conversion in hypotheses :n:`{+ @ident}`. always unfolded. .. example:: + .. coqtop:: all Definition volatile := fun x : nat => x. @@ -2890,6 +2924,7 @@ the conversion in hypotheses :n:`{+ @ident}`. such arguments. .. example:: + .. coqtop:: all Arguments minus !n !m. @@ -3168,7 +3203,7 @@ the :tacn:`auto` and :tacn:`trivial` tactics: .. opt:: Info Trivial .. opt:: Debug Trivial -See also: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` +.. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` .. tacn:: eauto :name: eauto @@ -3180,6 +3215,7 @@ where :tacn:`auto` uses simple :tacn:`apply`). As a consequence, :tacn:`eauto` can solve such a goal: .. example:: + .. coqtop:: all Hint Resolve ex_intro. @@ -3198,7 +3234,7 @@ Note that ``ex_intro`` should be declared as a hint. .. opt:: Info Eauto .. opt:: Debug Eauto -See also: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` +.. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` .. tacn:: autounfold with {+ @ident} @@ -3255,10 +3291,10 @@ command. Performs all the rewriting in the clause :n:`@clause`. The clause argument must not contain any ``type of`` nor ``value of``. -See also: :ref:`Hint-Rewrite <hintrewrite>` for feeding the database of lemmas used by -:tacn:`autorewrite`. +.. seealso:: -See also: :tacn:`autorewrite` for examples showing the use of this tactic. + :ref:`Hint-Rewrite <hintrewrite>` for feeding the database of lemmas used by + :tacn:`autorewrite` and :tacn:`autorewrite` for examples showing the use of this tactic. .. tacn:: easy :name: easy @@ -3554,7 +3590,7 @@ At Coq startup, only the core database is nonempty and can be used. :zarith: contains lemmas about binary signed integers from the directories theories/ZArith. When required, the module Omega also extends the database zarith with a high-cost hint that calls ``omega`` on equations - and inequalities in nat or Z. + and inequalities in ``nat`` or ``Z``. :bool: contains lemmas about booleans, mostly from directory theories/Bool. @@ -3564,7 +3600,7 @@ At Coq startup, only the core database is nonempty and can be used. :sets: contains lemmas about sets and relations from the directories Sets and Relations. -:typeclass_instances: contains all the type class instances declared in the +:typeclass_instances: contains all the typeclass instances declared in the environment, including those used for ``setoid_rewrite``, from the Classes directory. @@ -3693,7 +3729,7 @@ Setting implicit automation tactics In this case the tactic command typed by the user is equivalent to ``tactic``:sub:`1` ``;tactic``. - See also: ``Proof.`` in :ref:`proof-editing-mode`. + .. seealso:: :cmd:`Proof` in :ref:`proof-editing-mode`. .. cmdv:: Proof with tactic using {+ @ident} @@ -3748,6 +3784,7 @@ The following goal can be proved by :tacn:`tauto` whereas :tacn:`auto` would fail: .. example:: + .. coqtop:: reset all Goal forall (x:nat) (P:nat -> Prop), x = 0 \/ P x -> x <> 0 -> P x. @@ -3904,6 +3941,7 @@ equality must contain all the quantified variables in order for congruence to match against it. .. example:: + .. coqtop:: reset all Theorem T (A:Type) (f:A -> A) (g: A -> A -> A) a b: a=(f a) -> (g b (f a))=(f (f a)) -> (g a b)=(f (g b a)) -> (g a b)=a. @@ -3935,7 +3973,7 @@ match against it. discriminable equality but this proof could not be built in Coq because of dependently-typed functions. -.. exn:: Goal is solvable by congruence but some arguments are missing. Try congruence with ..., replacing metavariables by arbitrary terms. +.. exn:: Goal is solvable by congruence but some arguments are missing. Try congruence with {+ @term}, replacing metavariables by arbitrary terms. The decision procedure could solve the goal with the provision that additional arguments are supplied for some partially applied constructors. Any term of an @@ -3979,7 +4017,7 @@ succeeds, and results in an error otherwise. This tactic checks whether its arguments are unifiable, potentially instantiating existential variables. -.. exn:: Not unifiable. +.. exn:: Unable to unify @term with @term. .. tacv:: unify @term @term with @ident @@ -4165,8 +4203,9 @@ available after a ``Require Import FunInd``. .. tacv:: functional inversion @num - This does the same thing as intros until num thenfunctional inversion ident - where ident is the identifier for the last introduced hypothesis. + This does the same thing as :n:`intros until @num` folowed by + :n:`functional inversion @ident` where :token:`ident` is the + identifier for the last introduced hypothesis. .. tacv:: functional inversion ident qualid .. tacv:: functional inversion num qualid @@ -4273,7 +4312,7 @@ and :g:`Z` of binary integers. This tactic must be loaded by the command :name: ring_simplify The :n:`ring` tactic solves equations upon polynomial expressions of a ring -(or semi-ring) structure. It proceeds by normalizing both hand sides +(or semiring) structure. It proceeds by normalizing both hand sides of the equation (w.r.t. associativity, commutativity and distributivity, constant propagation) and comparing syntactically the results. @@ -4315,6 +4354,7 @@ declare new field structures. All declared field structures can be printed with the Print Fields command. .. example:: + .. coqtop:: reset all Require Import Reals. @@ -4325,8 +4365,10 @@ printed with the Print Fields command. intros; field. -See also: file plugins/setoid_ring/RealField.v for an example of instantiation, -theory theories/Reals for many examples of use of field. +.. seealso:: + + File plugins/setoid_ring/RealField.v for an example of instantiation, + theory theories/Reals for many examples of use of field. Non-logical tactics ------------------------ @@ -4426,6 +4468,7 @@ Simple tactic macros A simple example has more value than a long explanation: .. example:: + .. coqtop:: reset all Ltac Solve := simpl; intros; auto. @@ -4446,7 +4489,7 @@ user-defined tactics. other one can be automatically checked. .. [2] This corresponds to the cut rule of sequent calculus. .. [3] Reminder: opaque constants will not be expanded by δ reductions. -.. [4] The behavior of this tactic has much changed compared to the +.. [4] The behavior of this tactic has changed a lot compared to the versions available in the previous distributions (V6). This may cause significant changes in your theories to obtain the same result. As a drawback of the re-engineering of the code, this tactic has also been diff --git a/doc/sphinx/proof-engine/vernacular-commands.rst b/doc/sphinx/proof-engine/vernacular-commands.rst index 0a517973c2..584193b9c6 100644 --- a/doc/sphinx/proof-engine/vernacular-commands.rst +++ b/doc/sphinx/proof-engine/vernacular-commands.rst @@ -246,7 +246,7 @@ Requests to the environment hypothesis introduced in the first subgoal (if a proof is in progress). - See also: Section :ref:`performingcomputations`. + .. seealso:: Section :ref:`performingcomputations`. .. cmd:: Compute @term @@ -255,7 +255,7 @@ Requests to the environment bytecode-based virtual machine. It is a shortcut for ``Eval vm_compute in`` :n:`@term`. - See also: Section :ref:`performingcomputations`. + .. seealso:: Section :ref:`performingcomputations`. .. cmd:: Print Assumptions @qualid @@ -521,7 +521,7 @@ Requests to the environment This command displays the full name of objects whose name is a prefix of the qualified identifier :n:`@qualid`, and consequently the |Coq| module in which they are defined. It searches for objects from the different - qualified name spaces of |Coq|: terms, modules, Ltac, etc. + qualified namespaces of |Coq|: terms, modules, Ltac, etc. .. example:: @@ -549,7 +549,7 @@ Requests to the environment As Locate but restricted to tactics. -See also: Section :ref:`locating-notations` +.. seealso:: Section :ref:`locating-notations` .. _loading-files: @@ -587,7 +587,9 @@ toplevel. This kind of file is called a *script* for |Coq|. The standard Display, while loading, the answers of |Coq| to each command (including tactics) contained in - the loaded file See also: Section :ref:`controlling-display`. + the loaded file. + + .. seealso:: Section :ref:`controlling-display`. .. exn:: Can’t find file @ident on loadpath. @@ -699,10 +701,7 @@ file is a particular case of module called *library file*. that the commands ``Import`` and ``Export`` alone can be used inside modules (see Section :ref:`Import <import_qualid>`). - - -See also: Chapter :ref:`thecoqcommands` - + .. seealso:: Chapter :ref:`thecoqcommands` .. cmd:: Print Libraries @@ -930,7 +929,7 @@ Quitting and debugging .. cmd:: Drop - This is used mostly as a debug facility by |Coq|’s implementors and does + This is used mostly as a debug facility by |Coq|’s implementers and does not concern the casual user. This command permits to leave |Coq| temporarily and enter the OCaml toplevel. The OCaml command: @@ -1097,8 +1096,10 @@ described first. The scope of :cmd:`Opaque` is limited to the current section, or current file, unless the variant :cmd:`Global Opaque` is used. - See also: sections :ref:`performingcomputations`, :ref:`tactics-automating`, - :ref:`proof-editing-mode` + .. seealso:: + + Sections :ref:`performingcomputations`, :ref:`tactics-automating`, + :ref:`proof-editing-mode` .. exn:: The reference @qualid was not found in the current environment. @@ -1130,8 +1131,10 @@ described first. There is no constant referred by :n:`@qualid` in the environment. - See also: sections :ref:`performingcomputations`, - :ref:`tactics-automating`, :ref:`proof-editing-mode` + .. seealso:: + + Sections :ref:`performingcomputations`, + :ref:`tactics-automating`, :ref:`proof-editing-mode` .. _vernac-strategy: @@ -1195,7 +1198,7 @@ described first. nothing prevents the user to also perform a ``Ltac`` `ident` ``:=`` `convtactic`. - See also: sections :ref:`performingcomputations` + .. seealso:: :ref:`performingcomputations` .. _controlling-locality-of-commands: |