Merge branch 'master' of bitbucket.org:Peter_Sewell/sail

Conflicts:
	language/manual.pdf

1 files changed, 711 insertions, 1 deletions

diff --git a/src/lem_interp/interp_ast.lem b/src/lem_interp/interp_ast.lem
index 37719b1b..64fb14b2 120000..100644
--- a/src/lem_interp/interp_ast.lem
+++ b/src/lem_interp/interp_ast.lem
@@ -1 +1,711 @@
-../../language/l2.lem
\ No newline at end of file
+(*========================================================================*)
+(*     Sail                                                               *)
+(*                                                                        *)
+(*  Copyright (c) 2013-2017                                               *)
+(*    Kathyrn Gray                                                        *)
+(*    Shaked Flur                                                         *)
+(*    Stephen Kell                                                        *)
+(*    Gabriel Kerneis                                                     *)
+(*    Robert Norton-Wright                                                *)
+(*    Christopher Pulte                                                   *)
+(*    Peter Sewell                                                        *)
+(*                                                                        *)
+(*  All rights reserved.                                                  *)
+(*                                                                        *)
+(*  This software was developed by the University of Cambridge Computer   *)
+(*  Laboratory as part of the Rigorous Engineering of Mainstream Systems  *)
+(*  (REMS) project, funded by EPSRC grant EP/K008528/1.                   *)
+(*                                                                        *)
+(*  Redistribution and use in source and binary forms, with or without    *)
+(*  modification, are permitted provided that the following conditions    *)
+(*  are met:                                                              *)
+(*  1. Redistributions of source code must retain the above copyright     *)
+(*     notice, this list of conditions and the following disclaimer.      *)
+(*  2. Redistributions in binary form must reproduce the above copyright  *)
+(*     notice, this list of conditions and the following disclaimer in    *)
+(*     the documentation and/or other materials provided with the         *)
+(*     distribution.                                                      *)
+(*                                                                        *)
+(*  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''    *)
+(*  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED     *)
+(*  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A       *)
+(*  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR   *)
+(*  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,          *)
+(*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT      *)
+(*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF      *)
+(*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND   *)
+(*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,    *)
+(*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT    *)
+(*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF    *)
+(*  SUCH DAMAGE.                                                          *)
+(*========================================================================*)
+
+(* generated by Ott 0.25 from: l2_typ.ott l2.ott *)
+open import Pervasives
+
+open import Map
+open import Maybe
+open import Set_extra
+
+type l =
+  | Unknown
+  | Int of string * maybe l (*internal types, functions*)
+  | Range of string * nat * nat * nat * nat
+  | Generated of l (*location for a generated node, where l is the location of the closest original source*)
+
+type annot 'a = l * 'a
+
+val duplicates : forall 'a. list 'a -> list 'a
+
+val set_from_list : forall 'a. list 'a -> set 'a
+
+val subst : forall 'a. list 'a -> list 'a -> bool
+
+
+type x = string (* identifier *)
+type ix = string (* infix identifier *)
+
+type base_kind_aux =  (* base kind *)
+ | BK_type (* kind of types *)
+ | BK_nat (* kind of natural number size expressions *)
+ | BK_order (* kind of vector order specifications *)
+ | BK_effect (* kind of effect sets *)
+
+
+type base_kind = 
+ | BK_aux of base_kind_aux * l
+
+
+type kid_aux =  (* variables with kind, ticked to differntiate from program variables *)
+ | Var of x
+
+
+type id_aux =  (* Identifier *)
+ | Id of x
+ | DeIid of x (* remove infix status *)
+
+
+type kind_aux =  (* kinds *)
+ | K_kind of list base_kind
+
+
+type kid = 
+ | Kid_aux of kid_aux * l
+
+
+type id = 
+ | Id_aux of id_aux * l
+
+
+type kind = 
+ | K_aux of kind_aux * l
+
+
+type nexp_aux =  (* expression of kind Nat, for vector sizes and origins *)
+ | Nexp_id of id (* identifier, bound by def Nat x = nexp *)
+ | Nexp_var of kid (* variable *)
+ | Nexp_constant of integer (* constant *)
+ | Nexp_times of nexp * nexp (* product *)
+ | Nexp_sum of nexp * nexp (* sum *)
+ | Nexp_minus of nexp * nexp (* subtraction *)
+ | Nexp_exp of nexp (* exponential *)
+ | Nexp_neg of nexp (* For internal use *)
+
+and nexp = 
+ | Nexp_aux of nexp_aux * l
+
+
+type base_effect_aux =  (* effect *)
+ | BE_rreg (* read register *)
+ | BE_wreg (* write register *)
+ | BE_rmem (* read memory *)
+ | BE_wmem (* write memory *)
+ | BE_eamem (* signal effective address for writing memory *)
+ | BE_wmv (* write memory, sending only value *)
+ | BE_barr (* memory barrier *)
+ | BE_depend (* dynamic footprint *)
+ | BE_undef (* undefined-instruction exception *)
+ | BE_unspec (* unspecified values *)
+ | BE_nondet (* nondeterminism from intra-instruction parallelism *)
+ | BE_escape (* Tracking of expressions and functions that might call exit *)
+ | BE_lset (* Local mutation happend; not user-writable *)
+ | BE_lret (* Local return happened; not user-writable *)
+
+
+type base_effect = 
+ | BE_aux of base_effect_aux * l
+
+
+type order_aux =  (* vector order specifications, of kind Order *)
+ | Ord_var of kid (* variable *)
+ | Ord_inc (* increasing (little-endian) *)
+ | Ord_dec (* decreasing (big-endian) *)
+
+
+type effect_aux =  (* effect set, of kind Effects *)
+ | Effect_var of kid
+ | Effect_set of list base_effect (* effect set *)
+
+
+type order = 
+ | Ord_aux of order_aux * l
+
+
+type effect = 
+ | Effect_aux of effect_aux * l
+
+let effect_union e1 e2 = 
+  match (e1,e2) with
+  | ((Effect_aux (Effect_set els) _),(Effect_aux (Effect_set els2) l)) -> Effect_aux (Effect_set (els++els2)) l
+  end
+
+
+type kinded_id_aux =  (* optionally kind-annotated identifier *)
+ | KOpt_none of kid (* identifier *)
+ | KOpt_kind of kind * kid (* kind-annotated variable *)
+
+
+type n_constraint_aux =  (* constraint over kind $Nat$ *)
+ | NC_fixed of nexp * nexp
+ | NC_bounded_ge of nexp * nexp
+ | NC_bounded_le of nexp * nexp
+ | NC_nat_set_bounded of kid * list integer
+
+
+type kinded_id = 
+ | KOpt_aux of kinded_id_aux * l
+
+
+type n_constraint = 
+ | NC_aux of n_constraint_aux * l
+
+
+type quant_item_aux =  (* Either a kinded identifier or a nexp constraint for a typquant *)
+ | QI_id of kinded_id (* An optionally kinded identifier *)
+ | QI_const of n_constraint (* A constraint for this type *)
+
+
+type quant_item = 
+ | QI_aux of quant_item_aux * l
+
+
+type typquant_aux =  (* type quantifiers and constraints *)
+ | TypQ_tq of list quant_item
+ | TypQ_no_forall (* sugar, omitting quantifier and constraints *)
+
+
+type lit_aux =  (* Literal constant *)
+ | L_unit (* $() : unit$ *)
+ | L_zero (* $bitzero : bit$ *)
+ | L_one (* $bitone : bit$ *)
+ | L_true (* $true : bool$ *)
+ | L_false (* $false : bool$ *)
+ | L_num of integer (* natural number constant *)
+ | L_hex of string (* bit vector constant, C-style *)
+ | L_bin of string (* bit vector constant, C-style *)
+ | L_undef (* constant representing undefined values *)
+ | L_string of string (* string constant *)
+
+
+type typquant = 
+ | TypQ_aux of typquant_aux * l
+
+
+type typ_aux =  (* Type expressions, of kind $Type$ *)
+ | Typ_wild (* Unspecified type *)
+ | Typ_id of id (* Defined type *)
+ | Typ_var of kid (* Type variable *)
+ | Typ_fn of typ * typ * effect (* Function type (first-order only in user code) *)
+ | Typ_tup of list typ (* Tuple type *)
+ | Typ_app of id * list typ_arg (* type constructor application *)
+
+and typ = 
+ | Typ_aux of typ_aux * l
+
+and typ_arg_aux =  (* Type constructor arguments of all kinds *)
+ | Typ_arg_nexp of nexp
+ | Typ_arg_typ of typ
+ | Typ_arg_order of order
+ | Typ_arg_effect of effect
+
+and typ_arg = 
+ | Typ_arg_aux of typ_arg_aux * l
+
+
+type lit = 
+ | L_aux of lit_aux * l
+
+
+type typschm_aux =  (* type scheme *)
+ | TypSchm_ts of typquant * typ
+
+
+type pat_aux 'a =  (* Pattern *)
+ | P_lit of lit (* literal constant pattern *)
+ | P_wild (* wildcard *)
+ | P_as of (pat 'a) * id (* named pattern *)
+ | P_typ of typ * (pat 'a) (* typed pattern *)
+ | P_id of id (* identifier *)
+ | P_app of id * list (pat 'a) (* union constructor pattern *)
+ | P_record of list (fpat 'a) * bool (* struct pattern *)
+ | P_vector of list (pat 'a) (* vector pattern *)
+ | P_vector_indexed of list (integer * (pat 'a)) (* vector pattern (with explicit indices) *)
+ | P_vector_concat of list (pat 'a) (* concatenated vector pattern *)
+ | P_tup of list (pat 'a) (* tuple pattern *)
+ | P_list of list (pat 'a) (* list pattern *)
+
+and pat 'a = 
+ | P_aux of (pat_aux 'a) * annot 'a
+
+and fpat_aux 'a =  (* Field pattern *)
+ | FP_Fpat of id * (pat 'a)
+
+and fpat 'a = 
+ | FP_aux of (fpat_aux 'a) * annot 'a
+
+
+type typschm = 
+ | TypSchm_aux of typschm_aux * l
+
+
+type reg_id_aux 'a = 
+ | RI_id of id
+
+
+type exp_aux 'a =  (* Expression *)
+ | E_block of list (exp 'a) (* block *)
+ | E_nondet of list (exp 'a) (* nondeterminisitic block, expressions evaluate in an unspecified order, or concurrently *)
+ | E_id of id (* identifier *)
+ | E_lit of lit (* literal constant *)
+ | E_cast of typ * (exp 'a) (* cast *)
+ | E_app of id * list (exp 'a) (* function application *)
+ | E_app_infix of (exp 'a) * id * (exp 'a) (* infix function application *)
+ | E_tuple of list (exp 'a) (* tuple *)
+ | E_if of (exp 'a) * (exp 'a) * (exp 'a) (* conditional *)
+ | E_for of id * (exp 'a) * (exp 'a) * (exp 'a) * order * (exp 'a) (* loop *)
+ | E_vector of list (exp 'a) (* vector (indexed from 0) *)
+ | E_vector_indexed of list (integer * (exp 'a)) * (opt_default 'a) (* vector (indexed consecutively) *)
+ | E_vector_access of (exp 'a) * (exp 'a) (* vector access *)
+ | E_vector_subrange of (exp 'a) * (exp 'a) * (exp 'a) (* subvector extraction *)
+ | E_vector_update of (exp 'a) * (exp 'a) * (exp 'a) (* vector functional update *)
+ | E_vector_update_subrange of (exp 'a) * (exp 'a) * (exp 'a) * (exp 'a) (* vector subrange update (with vector) *)
+ | E_vector_append of (exp 'a) * (exp 'a) (* vector concatenation *)
+ | E_list of list (exp 'a) (* list *)
+ | E_cons of (exp 'a) * (exp 'a) (* cons *)
+ | E_record of (fexps 'a) (* struct *)
+ | E_record_update of (exp 'a) * (fexps 'a) (* functional update of struct *)
+ | E_field of (exp 'a) * id (* field projection from struct *)
+ | E_case of (exp 'a) * list (pexp 'a) (* pattern matching *)
+ | E_let of (letbind 'a) * (exp 'a) (* let expression *)
+ | E_assign of (lexp 'a) * (exp 'a) (* imperative assignment *)
+ | E_sizeof of nexp (* Expression to return the value of the nexp variable or expression at run time *)
+ | E_exit of (exp 'a) (* expression to halt all current execution, potentially calling a system, trap, or interrupt handler with exp *)
+ | E_return of (exp 'a) (* expression to end current function execution and return the value of exp from the function; this can be used to break out of for loops *)
+ | E_assert of (exp 'a) * (exp 'a) (* expression to halt with error, when the first expression is false, reporting the optional string as an error *)
+ | E_internal_cast of annot 'a * (exp 'a) (* This is an internal cast, generated during type checking that will resolve into a syntactic cast after *)
+ | E_internal_exp of annot 'a (* This is an internal use for passing nexp information  to library functions, postponed for constraint solving *)
+ | E_sizeof_internal of annot 'a (* For sizeof during type checking, to replace nexp with internal n *)
+ | E_internal_exp_user of annot 'a * annot 'a (* This is like the above but the user has specified an implicit parameter for the current function *)
+ | E_comment of string (* For generated unstructured comments *)
+ | E_comment_struc of (exp 'a) (* For generated structured comments *)
+ | E_internal_let of (lexp 'a) * (exp 'a) * (exp 'a) (* This is an internal node for compilation that demonstrates the scope of a local mutable variable *)
+ | E_internal_plet of (pat 'a) * (exp 'a) * (exp 'a) (* This is an internal node, used to distinguised some introduced lets during processing from original ones *)
+ | E_internal_return of (exp 'a) (* For internal use to embed into monad definition *)
+
+and exp 'a = 
+ | E_aux of (exp_aux 'a) * annot 'a
+
+and lexp_aux 'a =  (* lvalue expression *)
+ | LEXP_id of id (* identifier *)
+ | LEXP_memory of id * list (exp 'a) (* memory write via function call *)
+ | LEXP_cast of typ * id
+ | LEXP_tup of list (lexp 'a) (* set multiple at a time, a check will ensure it's not memory *)
+ | LEXP_vector of (lexp 'a) * (exp 'a) (* vector element *)
+ | LEXP_vector_range of (lexp 'a) * (exp 'a) * (exp 'a) (* subvector *)
+ | LEXP_field of (lexp 'a) * id (* struct field *)
+
+and lexp 'a = 
+ | LEXP_aux of (lexp_aux 'a) * annot 'a
+
+and fexp_aux 'a =  (* Field-expression *)
+ | FE_Fexp of id * (exp 'a)
+
+and fexp 'a = 
+ | FE_aux of (fexp_aux 'a) * annot 'a
+
+and fexps_aux 'a =  (* Field-expression list *)
+ | FES_Fexps of list (fexp 'a) * bool
+
+and fexps 'a = 
+ | FES_aux of (fexps_aux 'a) * annot 'a
+
+and opt_default_aux 'a =  (* Optional default value for indexed vectors, to define a defualt value for any unspecified positions in a sparse map *)
+ | Def_val_empty
+ | Def_val_dec of (exp 'a)
+
+and opt_default 'a = 
+ | Def_val_aux of (opt_default_aux 'a) * annot 'a
+
+and pexp_aux 'a =  (* Pattern match *)
+ | Pat_exp of (pat 'a) * (exp 'a)
+
+and pexp 'a = 
+ | Pat_aux of (pexp_aux 'a) * annot 'a
+
+and letbind_aux 'a =  (* Let binding *)
+ | LB_val_explicit of typschm * (pat 'a) * (exp 'a) (* value binding, explicit type ((pat 'a) must be total) *)
+ | LB_val_implicit of (pat 'a) * (exp 'a) (* value binding, implicit type ((pat 'a) must be total) *)
+
+and letbind 'a = 
+ | LB_aux of (letbind_aux 'a) * annot 'a
+
+
+type reg_id 'a = 
+ | RI_aux of (reg_id_aux 'a) * annot 'a
+
+
+type type_union_aux =  (* Type union constructors *)
+ | Tu_id of id
+ | Tu_ty_id of typ * id
+
+
+type name_scm_opt_aux =  (* Optional variable-naming-scheme specification for variables of defined type *)
+ | Name_sect_none
+ | Name_sect_some of string
+
+
+type effect_opt_aux =  (* Optional effect annotation for functions *)
+ | Effect_opt_pure (* sugar for empty effect set *)
+ | Effect_opt_effect of effect
+
+
+type funcl_aux 'a =  (* Function clause *)
+ | FCL_Funcl of id * (pat 'a) * (exp 'a)
+
+
+type rec_opt_aux =  (* Optional recursive annotation for functions *)
+ | Rec_nonrec (* non-recursive *)
+ | Rec_rec (* recursive *)
+
+
+type tannot_opt_aux =  (* Optional type annotation for functions *)
+ | Typ_annot_opt_some of typquant * typ
+
+
+type alias_spec_aux 'a =  (* Register alias expression forms. Other than where noted, each id must refer to an unaliased register of type vector *)
+ | AL_subreg of (reg_id 'a) * id
+ | AL_bit of (reg_id 'a) * (exp 'a)
+ | AL_slice of (reg_id 'a) * (exp 'a) * (exp 'a)
+ | AL_concat of (reg_id 'a) * (reg_id 'a)
+
+
+type type_union = 
+ | Tu_aux of type_union_aux * l
+
+
+type index_range_aux =  (* index specification, for bitfields in register types *)
+ | BF_single of integer (* single index *)
+ | BF_range of integer * integer (* index range *)
+ | BF_concat of index_range * index_range (* concatenation of index ranges *)
+
+and index_range = 
+ | BF_aux of index_range_aux * l
+
+
+type name_scm_opt = 
+ | Name_sect_aux of name_scm_opt_aux * l
+
+
+type effect_opt = 
+ | Effect_opt_aux of effect_opt_aux * l
+
+
+type funcl 'a = 
+ | FCL_aux of (funcl_aux 'a) * annot 'a
+
+
+type rec_opt = 
+ | Rec_aux of rec_opt_aux * l
+
+
+type tannot_opt = 
+ | Typ_annot_opt_aux of tannot_opt_aux * l
+
+
+type alias_spec 'a = 
+ | AL_aux of (alias_spec_aux 'a) * annot 'a
+
+
+type default_spec_aux 'a =  (* Default kinding or typing assumption *)
+ | DT_kind of base_kind * kid
+ | DT_order of order
+ | DT_typ of typschm * id
+
+
+type type_def_aux 'a =  (* Type definition body *)
+ | TD_abbrev of id * name_scm_opt * typschm (* type abbreviation *)
+ | TD_record of id * name_scm_opt * typquant * list (typ * id) * bool (* struct type definition *)
+ | TD_variant of id * name_scm_opt * typquant * list type_union * bool (* union type definition *)
+ | TD_enum of id * name_scm_opt * list id * bool (* enumeration type definition *)
+ | TD_register of id * nexp * nexp * list (index_range * id) (* register mutable bitfield type definition *)
+
+
+type val_spec_aux 'a =  (* Value type specification *)
+ | VS_val_spec of typschm * id
+ | VS_extern_no_rename of typschm * id
+ | VS_extern_spec of typschm * id * string (* Specify the type and id of a function from Lem, where the string must provide an explicit path to the required function but will not be checked *)
+
+
+type kind_def_aux 'a =  (* Definition body for elements of kind; many are shorthands for type\_defs *)
+ | KD_nabbrev of kind * id * name_scm_opt * nexp (* nexp abbreviation *)
+ | KD_abbrev of kind * id * name_scm_opt * typschm (* type abbreviation *)
+ | KD_record of kind * id * name_scm_opt * typquant * list (typ * id) * bool (* struct type definition *)
+ | KD_variant of kind * id * name_scm_opt * typquant * list type_union * bool (* union type definition *)
+ | KD_enum of kind * id * name_scm_opt * list id * bool (* enumeration type definition *)
+ | KD_register of kind * id * nexp * nexp * list (index_range * id) (* register mutable bitfield type definition *)
+
+
+type scattered_def_aux 'a =  (* Function and type union definitions that can be spread across
+         a file. Each one must end in $id$ *)
+ | SD_scattered_function of rec_opt * tannot_opt * effect_opt * id (* scattered function definition header *)
+ | SD_scattered_funcl of (funcl 'a) (* scattered function definition clause *)
+ | SD_scattered_variant of id * name_scm_opt * typquant (* scattered union definition header *)
+ | SD_scattered_unioncl of id * type_union (* scattered union definition member *)
+ | SD_scattered_end of id (* scattered definition end *)
+
+
+type fundef_aux 'a =  (* Function definition *)
+ | FD_function of rec_opt * tannot_opt * effect_opt * list (funcl 'a)
+
+
+type dec_spec_aux 'a =  (* Register declarations *)
+ | DEC_reg of typ * id
+ | DEC_alias of id * (alias_spec 'a)
+ | DEC_typ_alias of typ * id * (alias_spec 'a)
+
+
+type default_spec 'a = 
+ | DT_aux of (default_spec_aux 'a) * l
+
+
+type type_def 'a = 
+ | TD_aux of (type_def_aux 'a) * annot 'a
+
+
+type val_spec 'a = 
+ | VS_aux of (val_spec_aux 'a) * annot 'a
+
+
+type kind_def 'a = 
+ | KD_aux of (kind_def_aux 'a) * annot 'a
+
+
+type scattered_def 'a = 
+ | SD_aux of (scattered_def_aux 'a) * annot 'a
+
+
+type fundef 'a = 
+ | FD_aux of (fundef_aux 'a) * annot 'a
+
+
+type dec_spec 'a = 
+ | DEC_aux of (dec_spec_aux 'a) * annot 'a
+
+
+type dec_comm 'a =  (* Top-level generated comments *)
+ | DC_comm of string (* generated unstructured comment *)
+ | DC_comm_struct of (def 'a) (* generated structured comment *)
+
+and def 'a =  (* Top-level definition *)
+ | DEF_kind of (kind_def 'a) (* definition of named kind identifiers *)
+ | DEF_type of (type_def 'a) (* type definition *)
+ | DEF_fundef of (fundef 'a) (* function definition *)
+ | DEF_val of (letbind 'a) (* value definition *)
+ | DEF_spec of (val_spec 'a) (* top-level type constraint *)
+ | DEF_default of (default_spec 'a) (* default kind and type assumptions *)
+ | DEF_scattered of (scattered_def 'a) (* scattered function and type definition *)
+ | DEF_reg_dec of (dec_spec 'a) (* register declaration *)
+ | DEF_comm of (dec_comm 'a) (* generated comments *)
+
+
+type defs 'a =  (* Definition sequence *)
+ | Defs of list (def 'a)
+
+
+let rec remove_one i l =
+  match l with
+  | [] -> []
+  | i2::l2 -> if i2 = i then l2 else i2::(remove_one i l2)
+end
+
+let rec remove_from l l2 =
+  match l2 with 
+  | [] -> l
+  | i::l2' -> remove_from (remove_one i l) l2'
+end
+
+let disjoint s1 s2 = Set.null (s1 inter s2)
+
+let rec disjoint_all sets =
+  match sets with
+  | [] -> true
+  | s1::[] -> true
+  | s1::s2::sets -> (disjoint s1 s2) && (disjoint_all (s2::sets))
+end
+
+
+type ne =  (* internal numeric expressions *)
+ | Ne_id of x
+ | Ne_var of x
+ | Ne_const of integer
+ | Ne_inf
+ | Ne_mult of ne * ne
+ | Ne_add of list ne
+ | Ne_minus of ne * ne
+ | Ne_exp of ne
+ | Ne_unary of ne
+
+
+type k =  (* Internal kinds *)
+ | Ki_typ
+ | Ki_nat
+ | Ki_ord
+ | Ki_efct
+ | Ki_ctor of list k * k
+ | Ki_infer (* Representing an unknown kind, inferred by context *)
+
+
+type nec =  (* Numeric expression constraints *)
+ | Nec_lteq of ne * ne
+ | Nec_eq of ne * ne
+ | Nec_gteq of ne * ne
+ | Nec_in of x * list integer
+ | Nec_cond of list nec * list nec
+ | Nec_branch of list nec
+
+
+type tid =  (* A type identifier or type variable *)
+ | Tid_id of id
+ | Tid_var of kid
+
+
+type kinf =  (* Whether a kind is default or from a local binding *)
+ | Kinf_k of k
+ | Kinf_def of k
+
+
+type t =  (* Internal types *)
+ | T_id of x
+ | T_var of x
+ | T_fn of t * t * effect
+ | T_tup of list t
+ | T_app of x * t_args
+ | T_abbrev of t * t
+
+and t_arg =  (* Argument to type constructors *)
+ | T_arg_typ of t
+ | T_arg_nexp of ne
+ | T_arg_effect of effect
+ | T_arg_order of order
+
+and t_args =  (* Arguments to type constructors *)
+ | T_args of list t_arg
+
+
+type tag =  (* Data indicating where the identifier arises and thus information necessary in compilation *)
+ | Tag_empty
+ | Tag_intro (* Denotes an assignment and lexp that introduces a binding *)
+ | Tag_set (* Denotes an expression that mutates a local variable *)
+ | Tag_tuple_assign (* Denotes an assignment with a tuple lexp *)
+ | Tag_global (* Globally let-bound or enumeration based value/variable *)
+ | Tag_ctor (* Data constructor from a type union *)
+ | Tag_extern of maybe string (* External function, specied only with a val statement *)
+ | Tag_default (* Type has come from default declaration, identifier may not be bound locally *)
+ | Tag_spec
+ | Tag_enum of integer
+ | Tag_alias
+ | Tag_unknown of maybe string (* Tag to distinguish an unknown path from a non-analysis non deterministic path *)
+
+
+type tinf =  (* Type variables, type, and constraints, bound to an identifier *)
+ | Tinf_typ of t
+ | Tinf_quant_typ of (map tid kinf) * list nec * tag * t
+
+
+type conformsto =  (* how much conformance does overloading need *)
+ | Conformsto_full
+ | Conformsto_parm
+
+
+type widenvec = 
+ | Widenvec_widen
+ | Widenvec_dont
+ | Widenvec_dontcare
+
+
+type widennum = 
+ | Widennum_widen
+ | Widennum_dont
+ | Widennum_dontcare
+
+
+type tinflist =  (* In place so that a list of tinfs can be referred to without the dot form *)
+ | Tinfs_empty
+ | Tinfs_ls of list tinf
+
+
+type widening =  (* Should we widen vector start locations, should we widen atoms and ranges *)
+ | Widening_w of widennum * widenvec
+
+ type definition_env =
+   | DenvEmp
+   | Denv of (map tid kinf) * (map (list (id*t)) tinf) * (map t (list (nat*id)))
+
+
+let blength (bit) = Ne_const 8
+let hlength (bit) = Ne_const 8
+
+ type env =
+   | EnvEmp 
+   | Env of (map id tinf) * definition_env
+
+ type inf = 
+   | Iemp
+   | Inf of (list nec) * effect
+
+ val denv_union : definition_env -> definition_env -> definition_env
+ let denv_union de1 de2 = 
+  match (de1,de2) with
+   | (DenvEmp,de2) -> de2
+   | (de1,DenvEmp) -> de1
+   | ((Denv ke1 re1 ee1),(Denv ke2 re2 ee2)) ->
+      Denv (ke1 union ke2) (re1 union re2) (ee1 union ee2)
+   end
+
+ val env_union : env -> env -> env
+ let env_union e1 e2 =
+   match (e1,e2) with
+    | (EnvEmp,e2) -> e2
+    | (e1,EnvEmp) -> e1
+    | ((Env te1 de1),(Env te2 de2)) ->
+      Env (te1 union te2) (denv_union de1 de2)
+ end
+
+let inf_union i1 i2 =
+  match (i1,i2) with 
+ | (Iemp,i2) -> i2
+ | (i1,Iemp) -> i1
+ | (Inf n1 e1,Inf n2 e2) -> (Inf (n1++n2) (effect_union e1 e2))
+ end
+
+let fresh_kid denv = Var "x" (*TODO When strings can be manipulated, this should actually build a fresh string*)
+
+
+
+type E = env
+
+
+type I = inf
+
+
+