--- /dev/null
+(* Copyright (C) 2002, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://cs.unibo.it/helm/.
+ *)
+
+(******************************************************************************)
+(* *)
+(* PROJECT HELM *)
+(* *)
+(* Claudio Sacerdoti Coen <sacerdot@cs.unibo.it> *)
+(* 12/04/2002 *)
+(* *)
+(* *)
+(******************************************************************************)
+
+(* $Id$ *)
+
+(* The code of this module is derived from the code of CicReduction *)
+
+exception Impossible of int;;
+exception ReferenceToConstant;;
+exception ReferenceToVariable;;
+exception ReferenceToCurrentProof;;
+exception ReferenceToInductiveDefinition;;
+exception WrongUriToInductiveDefinition;;
+exception WrongUriToConstant;;
+exception RelToHiddenHypothesis;;
+
+module C = Cic
+module S = CicSubstitution
+
+let debug = false
+let prerr_endline =
+ if debug then prerr_endline else (fun x -> ())
+;;
+
+exception WhatAndWithWhatDoNotHaveTheSameLength;;
+
+(* Replaces "textually" in "where" every term in "what" with the corresponding
+ term in "with_what". The terms in "what" ARE NOT lifted when binders are
+ crossed. The terms in "with_what" ARE NOT lifted when binders are crossed.
+ Every free variable in "where" IS NOT lifted by nnn.
+*)
+let replace ~equality ~what ~with_what ~where =
+ let find_image t =
+ let rec find_image_aux =
+ function
+ [],[] -> raise Not_found
+ | what::tl1,with_what::tl2 ->
+ if equality what t then with_what else find_image_aux (tl1,tl2)
+ | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
+ in
+ find_image_aux (what,with_what)
+ in
+ let rec aux t =
+ try
+ find_image t
+ with Not_found ->
+ match t with
+ C.Rel _ -> t
+ | C.Var (uri,exp_named_subst) ->
+ C.Var (uri,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
+ | C.Meta _ -> t
+ | C.Sort _ -> t
+ | C.Implicit _ as t -> t
+ | C.Cast (te,ty) -> C.Cast (aux te, aux ty)
+ | C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
+ | C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
+ | C.LetIn (n,s,ty,t) -> C.LetIn (n, aux s, aux ty, aux t)
+ | C.Appl l ->
+ (* Invariant enforced: no application of an application *)
+ (match List.map aux l with
+ (C.Appl l')::tl -> C.Appl (l'@tl)
+ | l' -> C.Appl l')
+ | C.Const (uri,exp_named_subst) ->
+ C.Const (uri,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
+ | C.MutInd (uri,i,exp_named_subst) ->
+ C.MutInd
+ (uri,i,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
+ | C.MutConstruct (uri,i,j,exp_named_subst) ->
+ C.MutConstruct
+ (uri,i,j,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
+ | C.MutCase (sp,i,outt,t,pl) ->
+ C.MutCase (sp,i,aux outt, aux t,List.map aux pl)
+ | C.Fix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (name, i, aux ty, aux bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (name, aux ty, aux bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ aux where
+;;
+
+(* Replaces in "where" every term in "what" with the corresponding
+ term in "with_what". The terms in "what" ARE lifted when binders are
+ crossed. The terms in "with_what" ARE lifted when binders are crossed.
+ Every free variable in "where" IS NOT lifted by nnn.
+ Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
+ inverse of subst up to the fact that free variables in "where" are NOT
+ lifted. *)
+let replace_lifting ~equality ~context ~what ~with_what ~where =
+ let find_image ctx what t =
+ let rec find_image_aux =
+ function
+ [],[] -> raise Not_found
+ | what::tl1,with_what::tl2 ->
+ if equality ctx what t then with_what else find_image_aux (tl1,tl2)
+ | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
+ in
+ find_image_aux (what,with_what)
+ in
+ let add_ctx ctx n s = (Some (n, Cic.Decl s))::ctx in
+ let add_ctx1 ctx n s ty = (Some (n, Cic.Def (s,ty)))::ctx in
+ let rec substaux k ctx what t =
+ try
+ S.lift (k-1) (find_image ctx what t)
+ with Not_found ->
+ match t with
+ C.Rel n as t -> t
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k ctx what t) exp_named_subst
+ in
+ C.Var (uri,exp_named_subst')
+ | C.Meta (i, l) ->
+ let l' =
+ List.map
+ (function
+ None -> None
+ | Some t -> Some (substaux k ctx what t)
+ ) l
+ in
+ C.Meta(i,l')
+ | C.Sort _ as t -> t
+ | C.Implicit _ as t -> t
+ | C.Cast (te,ty) -> C.Cast (substaux k ctx what te, substaux k ctx what ty)
+ | C.Prod (n,s,t) ->
+ C.Prod
+ (n, substaux k ctx what s, substaux (k + 1) (add_ctx ctx n s) (List.map (S.lift 1) what) t)
+ | C.Lambda (n,s,t) ->
+ C.Lambda
+ (n, substaux k ctx what s, substaux (k + 1) (add_ctx ctx n s) (List.map (S.lift 1) what) t)
+ | C.LetIn (n,s,ty,t) ->
+ C.LetIn
+ (n, substaux k ctx what s, substaux k ctx what ty, substaux (k + 1) (add_ctx1 ctx n s ty) (List.map (S.lift 1) what) t)
+ | C.Appl (he::tl) ->
+ (* Invariant: no Appl applied to another Appl *)
+ let tl' = List.map (substaux k ctx what) tl in
+ begin
+ match substaux k ctx what he with
+ C.Appl l -> C.Appl (l@tl')
+ | _ as he' -> C.Appl (he'::tl')
+ end
+ | C.Appl _ -> assert false
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k ctx what t) exp_named_subst
+ in
+ C.Const (uri,exp_named_subst')
+ | C.MutInd (uri,i,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k ctx what t) exp_named_subst
+ in
+ C.MutInd (uri,i,exp_named_subst')
+ | C.MutConstruct (uri,i,j,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k ctx what t) exp_named_subst
+ in
+ C.MutConstruct (uri,i,j,exp_named_subst')
+ | C.MutCase (sp,i,outt,t,pl) ->
+ C.MutCase (sp,i,substaux k ctx what outt, substaux k ctx what t,
+ List.map (substaux k ctx what) pl)
+ | C.Fix (i,fl) ->
+ let len = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (* WRONG CTX *)
+ (name, i, substaux k ctx what ty,
+ substaux (k+len) ctx (List.map (S.lift len) what) bo)
+ ) fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let len = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (* WRONG CTX *)
+ (name, substaux k ctx what ty,
+ substaux (k+len) ctx (List.map (S.lift len) what) bo)
+ ) fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ substaux 1 context what where
+;;
+
+(* Replaces in "where" every term in "what" with the corresponding
+ term in "with_what". The terms in "what" ARE NOT lifted when binders are
+ crossed. The terms in "with_what" ARE lifted when binders are crossed.
+ Every free variable in "where" IS lifted by nnn.
+ Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
+ inverse of subst up to the fact that "what" terms are NOT lifted. *)
+let replace_lifting_csc nnn ~equality ~what ~with_what ~where =
+ let find_image t =
+ let rec find_image_aux =
+ function
+ [],[] -> raise Not_found
+ | what::tl1,with_what::tl2 ->
+ if equality what t then with_what else find_image_aux (tl1,tl2)
+ | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
+ in
+ find_image_aux (what,with_what)
+ in
+ let rec substaux k t =
+ try
+ S.lift (k-1) (find_image t)
+ with Not_found ->
+ match t with
+ C.Rel n ->
+ if n < k then C.Rel n else C.Rel (n + nnn)
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
+ in
+ C.Var (uri,exp_named_subst')
+ | C.Meta (i, l) ->
+ let l' =
+ List.map
+ (function
+ None -> None
+ | Some t -> Some (substaux k t)
+ ) l
+ in
+ C.Meta(i,l')
+ | C.Sort _ as t -> t
+ | C.Implicit _ as t -> t
+ | C.Cast (te,ty) -> C.Cast (substaux k te, substaux k ty)
+ | C.Prod (n,s,t) ->
+ C.Prod (n, substaux k s, substaux (k + 1) t)
+ | C.Lambda (n,s,t) ->
+ C.Lambda (n, substaux k s, substaux (k + 1) t)
+ | C.LetIn (n,s,ty,t) ->
+ C.LetIn (n, substaux k s, substaux k ty, substaux (k + 1) t)
+ | C.Appl (he::tl) ->
+ (* Invariant: no Appl applied to another Appl *)
+ let tl' = List.map (substaux k) tl in
+ begin
+ match substaux k he with
+ C.Appl l -> C.Appl (l@tl')
+ | _ as he' -> C.Appl (he'::tl')
+ end
+ | C.Appl _ -> assert false
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
+ in
+ C.Const (uri,exp_named_subst')
+ | C.MutInd (uri,i,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
+ in
+ C.MutInd (uri,i,exp_named_subst')
+ | C.MutConstruct (uri,i,j,exp_named_subst) ->
+ let exp_named_subst' =
+ List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
+ in
+ C.MutConstruct (uri,i,j,exp_named_subst')
+ | C.MutCase (sp,i,outt,t,pl) ->
+ C.MutCase (sp,i,substaux k outt, substaux k t,
+ List.map (substaux k) pl)
+ | C.Fix (i,fl) ->
+ let len = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) ->
+ (name, i, substaux k ty, substaux (k+len) bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let len = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) ->
+ (name, substaux k ty, substaux (k+len) bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ in
+ substaux 1 where
+;;
+
+(* This is like "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]"
+ up to the fact that the index to start from can be specified *)
+let replace_with_rel_1_from ~equality ~what =
+ let rec find_image t = function
+ | [] -> false
+ | hd :: tl -> equality t hd || find_image t tl
+ in
+ let rec subst_term k t =
+ if find_image t what then C.Rel k else inspect_term k t
+ and inspect_term k = function
+ | C.Rel i -> if i < k then C.Rel i else C.Rel (succ i)
+ | C.Sort _ as t -> t
+ | C.Implicit _ as t -> t
+ | C.Var (uri, enss) ->
+ let enss = List.map (subst_ens k) enss in
+ C.Var (uri, enss)
+ | C.Const (uri ,enss) ->
+ let enss = List.map (subst_ens k) enss in
+ C.Const (uri, enss)
+ | C.MutInd (uri, tyno, enss) ->
+ let enss = List.map (subst_ens k) enss in
+ C.MutInd (uri, tyno, enss)
+ | C.MutConstruct (uri, tyno, consno, enss) ->
+ let enss = List.map (subst_ens k) enss in
+ C.MutConstruct (uri, tyno, consno, enss)
+ | C.Meta (i, mss) ->
+ let mss = List.map (subst_ms k) mss in
+ C.Meta(i, mss)
+ | C.Cast (t, v) -> C.Cast (subst_term k t, subst_term k v)
+ | C.Appl ts ->
+ let ts = List.map (subst_term k) ts in
+ C.Appl ts
+ | C.MutCase (uri, tyno, outty, t, cases) ->
+ let cases = List.map (subst_term k) cases in
+ C.MutCase (uri, tyno, subst_term k outty, subst_term k t, cases)
+ | C.Prod (n, v, t) ->
+ C.Prod (n, subst_term k v, subst_term (succ k) t)
+ | C.Lambda (n, v, t) ->
+ C.Lambda (n, subst_term k v, subst_term (succ k) t)
+ | C.LetIn (n, v, ty, t) ->
+ C.LetIn (n, subst_term k v, subst_term k ty, subst_term (succ k) t)
+ | C.Fix (i, fixes) ->
+ let fixesno = List.length fixes in
+ let fixes = List.map (subst_fix fixesno k) fixes in
+ C.Fix (i, fixes)
+ | C.CoFix (i, cofixes) ->
+ let cofixesno = List.length cofixes in
+ let cofixes = List.map (subst_cofix cofixesno k) cofixes in
+ C.CoFix (i, cofixes)
+ and subst_ens k (uri, t) = uri, subst_term k t
+ and subst_ms k = function
+ | None -> None
+ | Some t -> Some (subst_term k t)
+ and subst_fix fixesno k (n, ind, ty, bo) =
+ n, ind, subst_term k ty, subst_term (k + fixesno) bo
+ and subst_cofix cofixesno k (n, ty, bo) =
+ n, subst_term k ty, subst_term (k + cofixesno) bo
+in
+subst_term
+
+let unfold ?what context where =
+ let contextlen = List.length context in
+ let first_is_the_expandable_head_of_second context' t1 t2 =
+ match t1,t2 with
+ Cic.Const (uri,_), Cic.Const (uri',_)
+ | Cic.Var (uri,_), Cic.Var (uri',_)
+ | Cic.Const (uri,_), Cic.Appl (Cic.Const (uri',_)::_)
+ | Cic.Var (uri,_), Cic.Appl (Cic.Var (uri',_)::_) -> UriManager.eq uri uri'
+ | Cic.Const _, _
+ | Cic.Var _, _ -> false
+ | Cic.Rel n, Cic.Rel m
+ | Cic.Rel n, Cic.Appl (Cic.Rel m::_) ->
+ n + (List.length context' - contextlen) = m
+ | Cic.Rel _, _ -> false
+ | _,_ ->
+ raise
+ (ProofEngineTypes.Fail
+ (lazy "The term to unfold is not a constant, a variable or a bound variable "))
+ in
+ let appl he tl =
+ if tl = [] then he else Cic.Appl (he::tl) in
+ let cannot_delta_expand t =
+ raise
+ (ProofEngineTypes.Fail
+ (lazy ("The term " ^ CicPp.ppterm t ^ " cannot be delta-expanded"))) in
+ let rec hd_delta_beta context tl =
+ function
+ Cic.Rel n as t ->
+ (try
+ match List.nth context (n-1) with
+ Some (_,Cic.Decl _) -> cannot_delta_expand t
+ | Some (_,Cic.Def (bo,_)) ->
+ CicReduction.head_beta_reduce
+ (appl (CicSubstitution.lift n bo) tl)
+ | None -> raise RelToHiddenHypothesis
+ with
+ Failure _ -> assert false)
+ | Cic.Const (uri,exp_named_subst) as t ->
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ (match o with
+ Cic.Constant (_,Some body,_,_,_) ->
+ CicReduction.head_beta_reduce
+ (appl (CicSubstitution.subst_vars exp_named_subst body) tl)
+ | Cic.Constant (_,None,_,_,_) -> cannot_delta_expand t
+ | Cic.Variable _ -> raise ReferenceToVariable
+ | Cic.CurrentProof _ -> raise ReferenceToCurrentProof
+ | Cic.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
+ )
+ | Cic.Var (uri,exp_named_subst) as t ->
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ (match o with
+ Cic.Constant _ -> raise ReferenceToConstant
+ | Cic.CurrentProof _ -> raise ReferenceToCurrentProof
+ | Cic.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
+ | Cic.Variable (_,Some body,_,_,_) ->
+ CicReduction.head_beta_reduce
+ (appl (CicSubstitution.subst_vars exp_named_subst body) tl)
+ | Cic.Variable (_,None,_,_,_) -> cannot_delta_expand t
+ )
+ | Cic.Appl [] -> assert false
+ | Cic.Appl (he::tl) -> hd_delta_beta context tl he
+ | t -> cannot_delta_expand t
+ in
+ let context_and_matched_term_list =
+ match what with
+ None -> [context, where]
+ | Some what ->
+ let res =
+ ProofEngineHelpers.locate_in_term
+ ~equality:first_is_the_expandable_head_of_second
+ what ~where context
+ in
+ if res = [] then
+ raise
+ (ProofEngineTypes.Fail
+ (lazy ("Term "^ CicPp.ppterm what ^ " not found in " ^ CicPp.ppterm where)))
+ else
+ res
+ in
+ let reduced_terms =
+ List.map
+ (function (context,where) -> hd_delta_beta context [] where)
+ context_and_matched_term_list in
+ let whats = List.map snd context_and_matched_term_list in
+ replace ~equality:(==) ~what:whats ~with_what:reduced_terms ~where
+;;
+
+exception WrongShape;;
+exception AlreadySimplified;;
+
+(* Takes a well-typed term and *)
+(* 1) Performs beta-iota-zeta reduction until delta reduction is needed *)
+(* 2) Attempts delta-reduction. If the residual is a Fix lambda-abstracted *)
+(* w.r.t. zero or more variables and if the Fix can be reductaed, than it*)
+(* is reduced, the delta-reduction is succesfull and the whole algorithm *)
+(* is applied again to the new redex; Step 3.1) is applied to the result *)
+(* of the recursive simplification. Otherwise, if the Fix can not be *)
+(* reduced, than the delta-reductions fails and the delta-redex is *)
+(* not reduced. Otherwise, if the delta-residual is not the *)
+(* lambda-abstraction of a Fix, then it performs step 3.2). *)
+(* 3.1) Folds the application of the constant to the arguments that did not *)
+(* change in every iteration, i.e. to the actual arguments for the *)
+(* lambda-abstractions that precede the Fix. *)
+(* 3.2) Computes the head beta-zeta normal form of the term. Then it tries *)
+(* reductions. If the reduction cannot be performed, it returns the *)
+(* original term (not the head beta-zeta normal form of the definiendum) *)
+(*CSC: It does not perform simplification in a Case *)
+
+let simpl context =
+ (* a simplified term is active if it can create a redex when used as an *)
+ (* actual parameter *)
+ let rec is_active =
+ function
+ C.Lambda _
+ | C.MutConstruct _
+ | C.Appl (C.MutConstruct _::_)
+ | C.CoFix _ -> true
+ | C.Cast (bo,_) -> is_active bo
+ | C.LetIn _ -> assert false
+ | _ -> false
+ in
+ (* reduceaux is equal to the reduceaux locally defined inside *)
+ (* reduce, but for the const case. *)
+ (**** Step 1 ****)
+ let rec reduceaux context l =
+ function
+ C.Rel n as t ->
+ (* we never perform delta expansion automatically *)
+ if l = [] then t else C.Appl (t::l)
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ reduceaux_exp_named_subst context l exp_named_subst
+ in
+ (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ match o with
+ C.Constant _ -> raise ReferenceToConstant
+ | C.CurrentProof _ -> raise ReferenceToCurrentProof
+ | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
+ | C.Variable (_,None,_,_,_) ->
+ let t' = C.Var (uri,exp_named_subst') in
+ if l = [] then t' else C.Appl (t'::l)
+ | C.Variable (_,Some body,_,_,_) ->
+ reduceaux context l
+ (CicSubstitution.subst_vars exp_named_subst' body)
+ )
+ | C.Meta _ as t -> if l = [] then t else C.Appl (t::l)
+ | C.Sort _ as t -> t (* l should be empty *)
+ | C.Implicit _ as t -> t
+ | C.Cast (te,ty) ->
+ C.Cast (reduceaux context l te, reduceaux context [] ty)
+ | C.Prod (name,s,t) ->
+ assert (l = []) ;
+ C.Prod (name,
+ reduceaux context [] s,
+ reduceaux ((Some (name,C.Decl s))::context) [] t)
+ | C.Lambda (name,s,t) ->
+ (match l with
+ [] ->
+ C.Lambda (name,
+ reduceaux context [] s,
+ reduceaux ((Some (name,C.Decl s))::context) [] t)
+ | he::tl -> reduceaux context tl (S.subst he t)
+ (* when name is Anonimous the substitution should be superfluous *)
+ )
+ | C.LetIn (n,s,ty,t) ->
+ reduceaux context l (S.subst (reduceaux context [] s) t)
+ | C.Appl (he::tl) ->
+ let tl' = List.map (reduceaux context []) tl in
+ reduceaux context (tl'@l) he
+ | C.Appl [] -> raise (Impossible 1)
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst' =
+ reduceaux_exp_named_subst context l exp_named_subst
+ in
+ (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ match o with
+ C.Constant (_,Some body,_,_,_) ->
+ if List.exists is_active l then
+ try_delta_expansion context l
+ (C.Const (uri,exp_named_subst'))
+ (CicSubstitution.subst_vars exp_named_subst' body)
+ else
+ let t' = C.Const (uri,exp_named_subst') in
+ if l = [] then t' else C.Appl (t'::l)
+ | C.Constant (_,None,_,_,_) ->
+ let t' = C.Const (uri,exp_named_subst') in
+ if l = [] then t' else C.Appl (t'::l)
+ | C.Variable _ -> raise ReferenceToVariable
+ | C.CurrentProof (_,_,body,_,_,_) -> reduceaux context l body
+ | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
+ )
+ | C.MutInd (uri,i,exp_named_subst) ->
+ let exp_named_subst' =
+ reduceaux_exp_named_subst context l exp_named_subst
+ in
+ let t' = C.MutInd (uri,i,exp_named_subst') in
+ if l = [] then t' else C.Appl (t'::l)
+ | C.MutConstruct (uri,i,j,exp_named_subst) ->
+ let exp_named_subst' =
+ reduceaux_exp_named_subst context l exp_named_subst
+ in
+ let t' = C.MutConstruct(uri,i,j,exp_named_subst') in
+ if l = [] then t' else C.Appl (t'::l)
+ | C.MutCase (mutind,i,outtype,term,pl) ->
+ let decofix =
+ function
+ C.CoFix (i,fl) ->
+ let (_,_,body) = List.nth fl i in
+ let body' =
+ let counter = ref (List.length fl) in
+ List.fold_right
+ (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
+ fl
+ body
+ in
+ reduceaux context [] body'
+ | C.Appl (C.CoFix (i,fl) :: tl) ->
+ let (_,_,body) = List.nth fl i in
+ let body' =
+ let counter = ref (List.length fl) in
+ List.fold_right
+ (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
+ fl
+ body
+ in
+ let tl' = List.map (reduceaux context []) tl in
+ reduceaux context tl' body'
+ | t -> t
+ in
+ (match decofix (reduceaux context [] term) (*(CicReduction.whd context term)*) with
+ C.MutConstruct (_,_,j,_) -> reduceaux context l (List.nth pl (j-1))
+ | C.Appl (C.MutConstruct (_,_,j,_) :: tl) ->
+ let (arity, r) =
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph mutind in
+ match o with
+ C.InductiveDefinition (tl,ingredients,r,_) ->
+ let (_,_,arity,_) = List.nth tl i in
+ (arity,r)
+ | _ -> raise WrongUriToInductiveDefinition
+ in
+ let ts =
+ let rec eat_first =
+ function
+ (0,l) -> l
+ | (n,he::tl) when n > 0 -> eat_first (n - 1, tl)
+ | _ -> raise (Impossible 5)
+ in
+ eat_first (r,tl)
+ in
+ reduceaux context (ts@l) (List.nth pl (j-1))
+ | C.Cast _ | C.Implicit _ ->
+ raise (Impossible 2) (* we don't trust our whd ;-) *)
+ | _ ->
+ let outtype' = reduceaux context [] outtype in
+ let term' = reduceaux context [] term in
+ let pl' = List.map (reduceaux context []) pl in
+ let res =
+ C.MutCase (mutind,i,outtype',term',pl')
+ in
+ if l = [] then res else C.Appl (res::l)
+ )
+ | C.Fix (i,fl) ->
+ let tys,_ =
+ List.fold_left
+ (fun (types,len) (n,_,ty,_) ->
+ (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
+ len+1)
+ ) ([],0) fl
+ in
+ let t' () =
+ let fl' =
+ List.map
+ (function (n,recindex,ty,bo) ->
+ (n,recindex,reduceaux context [] ty, reduceaux (tys@context) [] bo)
+ ) fl
+ in
+ C.Fix (i, fl')
+ in
+ let (_,recindex,_,body) = List.nth fl i in
+ let recparam =
+ try
+ Some (List.nth l recindex)
+ with
+ _ -> None
+ in
+ (match recparam with
+ Some recparam ->
+ (match reduceaux context [] recparam with
+ C.MutConstruct _
+ | C.Appl ((C.MutConstruct _)::_) ->
+ let body' =
+ let counter = ref (List.length fl) in
+ List.fold_right
+ (fun _ -> decr counter ; S.subst (C.Fix (!counter,fl)))
+ fl
+ body
+ in
+ (* Possible optimization: substituting whd recparam in l*)
+ reduceaux context l body'
+ | _ -> if l = [] then t' () else C.Appl ((t' ())::l)
+ )
+ | None -> if l = [] then t' () else C.Appl ((t' ())::l)
+ )
+ | C.CoFix (i,fl) ->
+ let tys,_ =
+ List.fold_left
+ (fun (types,len) (n,ty,_) ->
+ (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
+ len+1)
+ ) ([],0) fl
+ in
+ let t' =
+ let fl' =
+ List.map
+ (function (n,ty,bo) ->
+ (n,reduceaux context [] ty, reduceaux (tys@context) [] bo)
+ ) fl
+ in
+ C.CoFix (i, fl')
+ in
+ if l = [] then t' else C.Appl (t'::l)
+ and reduceaux_exp_named_subst context l =
+ List.map (function uri,t -> uri,reduceaux context [] t)
+ (**** Step 2 ****)
+ and reduce_with_no_hope_to_fold_back t l =
+ prerr_endline "reduce_with_no_hope_to_fold_back";
+ let simplified = reduceaux context l t in
+ let t' = if l = [] then t else C.Appl (t::l) in
+ if t' = simplified then
+ raise AlreadySimplified
+ else
+ simplified
+
+ and try_delta_expansion context l term body =
+ try
+ let res,constant_args =
+ let rec aux rev_constant_args l =
+ function
+ C.Lambda (name,s,t) ->
+ begin
+ match l with
+ [] -> raise WrongShape
+ | he::tl ->
+ (* when name is Anonimous the substitution should *)
+ (* be superfluous *)
+ aux (he::rev_constant_args) tl (S.subst he t)
+ end
+ | C.LetIn (_,s,_,t) ->
+ aux rev_constant_args l (S.subst s t)
+ | C.Fix (i,fl) ->
+ let (_,recindex,_,body) = List.nth fl i in
+ let recparam =
+ try
+ List.nth l recindex
+ with
+ _ -> raise AlreadySimplified
+ in
+ (match reduceaux context [] recparam (*CicReduction.whd context recparam*) with
+ C.MutConstruct _
+ | C.Appl ((C.MutConstruct _)::_) ->
+ let body' =
+ let counter = ref (List.length fl) in
+ List.fold_right
+ (function _ ->
+ decr counter ; S.subst (C.Fix (!counter,fl))
+ ) fl body
+ in
+ (* Possible optimization: substituting whd *)
+ (* recparam in l *)
+ reduceaux context l body',
+ List.rev rev_constant_args
+ | _ -> raise AlreadySimplified
+ )
+ | _ -> raise WrongShape
+ in
+ aux [] l body
+ in
+ (**** Step 3.1 ****)
+ let term_to_fold, delta_expanded_term_to_fold =
+ match constant_args with
+ [] -> term,body
+ | _ -> C.Appl (term::constant_args), C.Appl (body::constant_args)
+ in
+ let simplified_term_to_fold =
+ reduceaux context [] delta_expanded_term_to_fold
+ in
+ replace_lifting ~equality:(fun _ x y -> x = y) ~context
+ ~what:[simplified_term_to_fold] ~with_what:[term_to_fold] ~where:res
+ with
+ WrongShape ->
+ let rec skip_lambda n = function
+ | Cic.Lambda (_,_,t) -> skip_lambda (n+1) t | t -> t, n
+ in
+ let is_fix uri =
+ match fst(CicEnvironment.get_obj CicUniv.oblivion_ugraph uri) with
+ | Cic.Constant (_,Some bo, _, _,_) ->
+ (let t, _ = skip_lambda 0 bo in
+ match t with | Cic.Fix _ -> true | _ -> false)
+ | _ -> false
+ in
+ let guess_recno uri =
+ prerr_endline ("GUESS: " ^ UriManager.string_of_uri uri);
+ match fst(CicEnvironment.get_obj CicUniv.oblivion_ugraph uri) with
+ | Cic.Constant (_,Some bo, _, _,_ ) ->
+ let t, n = skip_lambda 0 bo in
+ (match t with
+ | Cic.Fix (i,fl) ->
+ let _,recno,_,_ = List.nth fl i in
+ prerr_endline ("GUESSED: " ^ string_of_int recno ^ " after " ^
+ string_of_int n ^ " lambdas");
+ recno + n
+ | _ -> assert false)
+ | _ -> assert false
+ in
+ let original_args = l in
+ (**** Step 3.2 ****)
+ let rec aux l =
+ function
+ | C.Lambda (name,s,t) ->
+ (match l with
+ | [] -> raise AlreadySimplified
+ | he::tl ->
+ (* when name is Anonimous the substitution should *)
+ (* be superfluous *)
+ aux tl (S.subst he t))
+ | C.LetIn (_,s,_,t) -> aux l (S.subst s t)
+ | Cic.Appl (Cic.Const (uri,_) :: args) as t when is_fix uri ->
+ let recno =
+ prerr_endline ("cerco : " ^ string_of_int (guess_recno uri)
+ ^ " in: " ^ String.concat " "
+ (List.map (fun x -> CicPp.ppterm x) args));
+ prerr_endline ("e piglio il rispettivo in :"^String.concat " "
+ (List.map (fun x -> CicPp.ppterm x) original_args));
+ (* look for args[regno] in saved_args *)
+ let wanted = List.nth (args@l) (guess_recno uri) in
+ let rec aux n = function
+ | [] -> n (* DA CAPIRE *)
+ | t::_ when t = wanted -> n
+ | _::tl -> aux (n+1) tl
+ in
+ aux 0 original_args
+ in
+ if recno = List.length original_args then
+ reduce_with_no_hope_to_fold_back t l
+ else
+ let simplified = reduceaux context l t in
+ let rec mk_implicits = function
+ | n,_::tl when n = recno ->
+ Cic.Implicit None :: (mk_implicits (n+1,tl))
+ | n,arg::tl -> arg :: (mk_implicits (n+1,tl))
+ | _,[] -> []
+ in
+ (* we try to fold back constant that do not expand to Fix *)
+ let _ = prerr_endline
+ ("INIZIO (" ^ string_of_int recno ^ ") : " ^ CicPp.ppterm
+ simplified) in
+ let term_to_fold =
+ Cic.Appl (term:: mk_implicits (0,original_args))
+ in
+ (try
+ let term_to_fold, _, metasenv, _ =
+ CicRefine.type_of_aux' [] context term_to_fold
+ CicUniv.oblivion_ugraph
+ in
+ let _ =
+ prerr_endline ("RAFFINA: "^CicPp.ppterm term_to_fold) in
+ let _ =
+ prerr_endline
+ ("RAFFINA: "^CicMetaSubst.ppmetasenv [] metasenv) in
+ let simplified_term_to_fold = unfold context term_to_fold in
+ let _ =
+ prerr_endline ("SEMPLIFICA: " ^
+ CicPp.ppterm simplified_term_to_fold)
+ in
+ let rec do_n f t =
+ let t1 = f t in
+ if t1 = t then t else do_n f t1
+ in
+ do_n
+ (fun simplified ->
+ let subst = ref [] in
+ let myunif ctx t1 t2 =
+ if !subst <> [] then false
+ else
+ try
+ prerr_endline "MUNIF";
+ prerr_endline (CicPp.ppterm t1);
+ prerr_endline "VS";
+ prerr_endline (CicPp.ppterm t2 ^ "\n");
+ let subst1, _, _ =
+ CicUnification.fo_unif metasenv ctx t1 t2
+ CicUniv.empty_ugraph
+ in
+ prerr_endline "UNIFICANO\n\n\n";
+ subst := subst1;
+ true
+ with
+ | CicUnification.UnificationFailure s
+ | CicUnification.Uncertain s
+ | CicUnification.AssertFailure s ->
+ prerr_endline (Lazy.force s); false
+ | CicUtil.Meta_not_found _ -> false
+ (*
+ | _ as exn ->
+ prerr_endline (Printexc.to_string exn);
+ false*)
+ in
+ let t =
+ replace_lifting myunif context
+ [simplified_term_to_fold] [term_to_fold] simplified
+ in
+ let _ = prerr_endline "UNIFICA" in
+ if List.length metasenv <> List.length !subst then
+ let _ = prerr_endline ("SUBST CORTA " ^
+ CicMetaSubst.ppsubst !subst ~metasenv)
+ in
+ simplified
+ else
+ if t = simplified then
+ let _ = prerr_endline "NULLA DI FATTO" in
+ simplified
+ else
+ let t = CicMetaSubst.apply_subst !subst t in
+ prerr_endline ("ECCO: " ^ CicPp.ppterm t); t)
+ simplified
+ with
+ | CicRefine.RefineFailure s
+ | CicRefine.Uncertain s
+ | CicRefine.AssertFailure s ->
+ prerr_endline (Lazy.force s); simplified
+ (*| exn -> prerr_endline (Printexc.to_string exn); simplified*))
+ | t -> reduce_with_no_hope_to_fold_back t l
+ in
+ (try aux l body
+ with
+ AlreadySimplified ->
+ if l = [] then term else C.Appl (term::l))
+ | AlreadySimplified ->
+ (* If we performed delta-reduction, we would find a Fix *)
+ (* not applied to a constructor. So, we refuse to perform *)
+ (* delta-reduction. *)
+ if l = [] then term else C.Appl (term::l)
+ in
+ reduceaux context []
+;;
projects / helm.git / blobdiff