X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Ftactics%2FproofEngineReduction.ml;h=f8782b7aec13db70083d025a44258d1416d0cf21;hb=938afa2d17a731cef4b7226aa9c1bc7c3b7de2fe;hp=8a6ef81a277658d5e7cda8055768a925b7b3e574;hpb=d774aa49f50598f725ded815b87949110a6acdcf;p=helm.git diff --git a/helm/ocaml/tactics/proofEngineReduction.ml b/helm/ocaml/tactics/proofEngineReduction.ml index 8a6ef81a2..f8782b7ae 100644 --- a/helm/ocaml/tactics/proofEngineReduction.ml +++ b/helm/ocaml/tactics/proofEngineReduction.ml @@ -127,7 +127,7 @@ let replace ~equality ~what ~with_what ~where = function [],[] -> raise Not_found | what::tl1,with_what::tl2 -> - if equality t what then with_what else find_image_aux (tl1,tl2) + if equality what t then with_what else find_image_aux (tl1,tl2) | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength in find_image_aux (what,with_what) @@ -190,7 +190,7 @@ let replace_lifting ~equality ~what ~with_what ~where = function [],[] -> raise Not_found | what::tl1,with_what::tl2 -> - if equality t what then with_what else find_image_aux (tl1,tl2) + if equality what t then with_what else find_image_aux (tl1,tl2) | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength in find_image_aux (what,with_what) @@ -288,7 +288,7 @@ let replace_lifting_csc nnn ~equality ~what ~with_what ~where = function [],[] -> raise Not_found | what::tl1,with_what::tl2 -> - if equality t what then with_what else find_image_aux (tl1,tl2) + if equality what t then with_what else find_image_aux (tl1,tl2) | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength in find_image_aux (what,with_what) @@ -583,8 +583,11 @@ exception AlreadySimplified;; (* Takes a well-typed term and *) (* 1) Performs beta-iota-zeta reduction until delta reduction is needed *) +(* Zeta-reduction is performed if and only if the simplified form of its *) +(* definiendum (applied to the actual arguments) is different from the *) +(* non-simplified form. *) (* 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 *) +(* 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) is applied to the result *) (* of the recursive simplification. Otherwise, if the Fix can not be *) @@ -598,6 +601,14 @@ exception AlreadySimplified;; (*CSC: It does not perform simplification in a Case *) let simpl context = + let mk_appl t l = + if l = [] then + t + else + match t with + | Cic.Appl l' -> Cic.Appl (l'@l) + | _ -> Cic.Appl (t::l) + in (* reduceaux is equal to the reduceaux locally defined inside *) (* reduce, but for the const case. *) (**** Step 1 ****) @@ -610,7 +621,13 @@ let simpl context = match List.nth context (n-1) with Some (_,C.Decl _) -> if l = [] then t else C.Appl (t::l) | Some (_,C.Def (bo,_)) -> - try_delta_expansion context l t (S.lift n bo) + let lifted_bo = S.lift n bo in + let applied_lifted_bo = mk_appl lifted_bo l in + let simplified = try_delta_expansion context l t lifted_bo in + if simplified = applied_lifted_bo then + if l = [] then t else C.Appl (t::l) + else + simplified | None -> raise RelToHiddenHypothesis with Failure _ -> assert false) @@ -714,7 +731,7 @@ let simpl context = reduceaux context tl body' | t -> t in - (match decofix (reduceaux context [] term) with + (match decofix (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) = @@ -874,3 +891,90 @@ let simpl context = in reduceaux context [] ;; + +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 + "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 + ("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 + ("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 +;;