--- /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/.
+ *)
+
+(* $Id$ *)
+
+open ProofEngineTypes
+
+(* Note: this code is almost identical to change_tac and
+* it could be unified by making the change function a callback *)
+let reduction_tac ~reduction ~pattern (proof,goal) =
+ let curi,metasenv,_subst,pbo,pty, attrs = proof in
+ let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
+ let change subst where terms metasenv ugraph =
+ if terms = [] then where, metasenv, ugraph
+ else
+ let pairs, metasenv, ugraph =
+ List.fold_left
+ (fun (pairs, metasenv, ugraph) (context, t) ->
+ let reduction, metasenv, ugraph = reduction context metasenv ugraph in
+ ((t, reduction context t) :: pairs), metasenv, ugraph)
+ ([], metasenv, ugraph)
+ terms
+ in
+ let terms, terms' = List.split pairs in
+ let where' =
+ ProofEngineReduction.replace ~equality:(==) ~what:terms ~with_what:terms'
+ ~where:where
+ in
+ CicMetaSubst.apply_subst subst where', metasenv, ugraph
+ in
+ let (subst,metasenv,ugraph,selected_context,selected_ty) =
+ ProofEngineHelpers.select ~metasenv ~ugraph:CicUniv.empty_ugraph
+ ~conjecture ~pattern
+ in
+ let ty', metasenv, ugraph = change subst ty selected_ty metasenv ugraph in
+ let context', metasenv, ugraph =
+ List.fold_right2
+ (fun entry selected_entry (context', metasenv, ugraph) ->
+ match entry,selected_entry with
+ None,None -> None::context', metasenv, ugraph
+ | Some (name,Cic.Decl ty),Some (`Decl selected_ty) ->
+ let ty', metasenv, ugraph =
+ change subst ty selected_ty metasenv ugraph
+ in
+ Some (name,Cic.Decl ty')::context', metasenv, ugraph
+ | Some (name,Cic.Def (bo,ty)),Some (`Def (selected_bo,selected_ty)) ->
+ let bo', metasenv, ugraph =
+ change subst bo selected_bo metasenv ugraph in
+ let ty', metasenv, ugraph =
+ change subst ty selected_ty metasenv ugraph
+ in
+ (Some (name,Cic.Def (bo',ty'))::context'), metasenv, ugraph
+ | _,_ -> assert false
+ ) context selected_context ([], metasenv, ugraph) in
+ let metasenv' =
+ List.map (function
+ | (n,_,_) when n = metano -> (metano,context',ty')
+ | _ as t -> t
+ ) metasenv
+ in
+ (curi,metasenv',_subst,pbo,pty, attrs), [metano]
+;;
+
+let simpl_tac ~pattern =
+ mk_tactic (reduction_tac
+ ~reduction:(const_lazy_reduction ProofEngineReduction.simpl) ~pattern)
+
+let unfold_tac what ~pattern =
+ let reduction =
+ match what with
+ | None -> const_lazy_reduction (ProofEngineReduction.unfold ?what:None)
+ | Some lazy_term ->
+ (fun context metasenv ugraph ->
+ let what, metasenv, ugraph = lazy_term context metasenv ugraph in
+ let unfold ctx t =
+ try
+ ProofEngineReduction.unfold ~what ctx t
+ with
+ (* Not what we would like to have; however, this is required
+ right now for the case of a definition in the context:
+ if it works only in the body (or only in the type), that should
+ be accepted *)
+ ProofEngineTypes.Fail _ -> t
+ in
+ unfold, metasenv, ugraph)
+ in
+ mk_tactic (reduction_tac ~reduction ~pattern)
+
+let whd_tac ~pattern =
+ mk_tactic (reduction_tac
+ ~reduction:(const_lazy_reduction CicReduction.whd) ~pattern)
+
+let normalize_tac ~pattern =
+ mk_tactic (reduction_tac
+ ~reduction:(const_lazy_reduction CicReduction.normalize) ~pattern)
+
+let head_beta_reduce_tac ?delta ?upto ~pattern =
+ mk_tactic (reduction_tac
+ ~reduction:
+ (const_lazy_reduction
+ (fun _context -> CicReduction.head_beta_reduce ?delta ?upto)) ~pattern)
+
+exception NotConvertible
+
+(* Note: this code is almost identical to reduction_tac and
+* it could be unified by making the change function a callback *)
+(* CSC: with_what is parsed in the context of the goal, but it should replace
+ something that lives in a completely different context. Thus we
+ perform a delift + lift phase to move it in the right context. However,
+ in this way the tactic is less powerful than expected: with_what cannot
+ reference variables that are local to the term that is going to be
+ replaced. To fix this we should parse with_what in the context of the
+ term(s) to be replaced. *)
+let change_tac ?(with_cast=false) ~pattern with_what =
+ let change_tac ~pattern ~with_what (proof, goal) =
+ let curi,metasenv,_subst,pbo,pty, attrs = proof in
+ let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
+ let change subst where terms metasenv ugraph =
+ if terms = [] then where, metasenv, ugraph
+ else
+ let pairs, metasenv, ugraph =
+ List.fold_left
+ (fun (pairs, metasenv, ugraph) (context_of_t, t) ->
+ let with_what, metasenv, ugraph =
+ with_what context_of_t metasenv ugraph
+ in
+ let _,u =
+ CicTypeChecker.type_of_aux' metasenv context_of_t with_what ugraph
+ in
+ let b,_ =
+ CicReduction.are_convertible ~metasenv context_of_t t with_what u
+ in
+ if b then
+ ((t, with_what) :: pairs), metasenv, ugraph
+ else
+ raise NotConvertible)
+ ([], metasenv, ugraph)
+ terms
+ in
+ let terms, terms' = List.split pairs in
+ let where' =
+ ProofEngineReduction.replace ~equality:(==) ~what:terms ~with_what:terms'
+ ~where:where
+ in
+ CicMetaSubst.apply_subst subst where', metasenv, ugraph
+ in
+ let (subst,metasenv,ugraph,selected_context,selected_ty) =
+ ProofEngineHelpers.select ~metasenv ~ugraph:CicUniv.empty_ugraph ~conjecture
+ ~pattern in
+ let ty', metasenv, ugraph = change subst ty selected_ty metasenv ugraph in
+ let context', metasenv, ugraph =
+ List.fold_right2
+ (fun entry selected_entry (context', metasenv, ugraph) ->
+ match entry,selected_entry with
+ None,None -> (None::context'), metasenv, ugraph
+ | Some (name,Cic.Decl ty),Some (`Decl selected_ty) ->
+ let ty', metasenv, ugraph =
+ change subst ty selected_ty metasenv ugraph
+ in
+ (Some (name,Cic.Decl ty')::context'), metasenv, ugraph
+ | Some (name,Cic.Def (bo,ty)),Some (`Def (selected_bo,selected_ty)) ->
+ let bo', metasenv, ugraph =
+ change subst bo selected_bo metasenv ugraph in
+ let ty', metasenv, ugraph =
+ change subst ty selected_ty metasenv ugraph
+ in
+ (Some (name,Cic.Def (bo',ty'))::context'), metasenv, ugraph
+ | _,_ -> assert false
+ ) context selected_context ([], metasenv, ugraph) in
+ let metasenv' =
+ List.map
+ (function
+ | (n,_,_) when n = metano -> (metano,context',ty')
+ | _ as t -> t)
+ metasenv
+ in
+ let proof,goal = (curi,metasenv',_subst,pbo,pty, attrs), metano in
+ if with_cast then
+ let metano' = ProofEngineHelpers.new_meta_of_proof ~proof in
+ let (newproof,_) =
+ let irl= CicMkImplicit.identity_relocation_list_for_metavariable context'
+ in
+ ProofEngineHelpers.subst_meta_in_proof
+ proof metano
+ (Cic.Cast (Cic.Meta(metano',irl),ty')) [metano',context',ty']
+ in
+ newproof, [metano']
+ else
+ proof,[goal]
+ in
+ mk_tactic (change_tac ~pattern ~with_what)
+
+let fold_tac ~reduction ~term ~pattern =
+ let fold_tac ~reduction ~term ~pattern:(wanted,hyps_pat,concl_pat) status =
+ assert (wanted = None); (* this should be checked syntactically *)
+ let reduced_term =
+ (fun context metasenv ugraph ->
+ let term, metasenv, ugraph = term context metasenv ugraph in
+ let reduction, metasenv, ugraph = reduction context metasenv ugraph in
+ reduction context term, metasenv, ugraph)
+ in
+ apply_tactic
+ (change_tac ~pattern:(Some reduced_term,hyps_pat,concl_pat) term) status
+ in
+ mk_tactic (fold_tac ~reduction ~term ~pattern)
+
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