From: Stefano Zacchiroli Date: Thu, 15 Sep 2005 12:12:30 +0000 (+0000) Subject: bugfix in discriminate: now works also with inductive types with left parameters X-Git-Tag: LAST_BEFORE_NEW~124 X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=66496e0c92e31547de2bd84defe0d83bc8bf49ea;p=helm.git bugfix in discriminate: now works also with inductive types with left parameters discriminate code has also been re-engineered and re-formatted --- diff --git a/helm/ocaml/tactics/discriminationTactics.ml b/helm/ocaml/tactics/discriminationTactics.ml index a26895e62..1a05bce1b 100644 --- a/helm/ocaml/tactics/discriminationTactics.ml +++ b/helm/ocaml/tactics/discriminationTactics.ml @@ -194,140 +194,140 @@ and injection1_tac ~term ~i = ProofEngineTypes.mk_tactic (injection1_tac ~term ~i) ;; - - exception TwoDifferentSubtermsFound of int (* term ha tipo t1=t2; funziona solo se t1 e t2 hanno in testa costruttori diversi *) let discriminate'_tac ~term = + let module C = Cic in + let module U = UriManager in + let module P = PrimitiveTactics in + let module T = Tacticals in + let fail msg = raise (ProofEngineTypes.Fail ("Discriminate: " ^ msg)) in + let find_discriminating_consno t1 t2 = + let rec aux t1 t2 = + match t1, t2 with + | C.MutConstruct _, C.MutConstruct _ when t1 = t2 -> None + | C.Appl ((C.MutConstruct _ as constr1) :: args1), + C.Appl ((C.MutConstruct _ as constr2) :: args2) + when constr1 = constr2 -> + let rec aux_list l1 l2 = + match l1, l2 with + | [], [] -> None + | hd1 :: tl1, hd2 :: tl2 -> + (match aux hd1 hd2 with + | None -> aux_list tl1 tl2 + | Some _ as res -> res) + | _ -> (* same constructor applied to a different number of args *) + assert false + in + aux_list args1 args2 + | ((C.MutConstruct (_,_,consno1,subst1)), + (C.MutConstruct (_,_,consno2,subst2))) + | ((C.MutConstruct (_,_,consno1,subst1)), + (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _))) + | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)), + (C.MutConstruct (_,_,consno2,subst2))) + | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)), + (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _))) + when (consno1 <> consno2) || (subst1 <> subst2) -> + Some consno2 + | _ -> fail "not a discriminable equality" + in + aux t1 t2 + in + let mk_pattern turi typeno consno context left_args = + (* a list of "True" except for the element in position consno which + * is "False" *) + match fst (CicEnvironment.get_obj CicUniv.empty_ugraph turi) with + | C.InductiveDefinition (ind_type_list,_,nr_ind_params,_) -> + let _,_,_,constructor_list = List.nth ind_type_list typeno in + let false_constr_id,_ = List.nth constructor_list (consno - 1) in + List.map + (fun (id,cty) -> + (* dubbio: e' corretto ridurre in questo context ??? *) + let red_ty = CicReduction.whd context cty in + let rec aux t k = + match t with + | C.Prod (_,_,target) when (k <= nr_ind_params) -> + CicSubstitution.subst (List.nth left_args (k-1)) + (aux target (k+1)) + | C.Prod (binder,source,target) when (k > nr_ind_params) -> + C.Lambda (binder, source, (aux target (k+1))) + | _ -> + if (id = false_constr_id) + then (C.MutInd(LibraryObjects.false_URI (),0,[])) + else (C.MutInd(LibraryObjects.true_URI (),0,[])) + in + (CicSubstitution.lift 1 (aux red_ty 1))) + constructor_list + | _ -> (* object is not an inductive definition *) + assert false + in let discriminate'_tac ~term status = let (proof, goal) = status in - let module C = Cic in - let module U = UriManager in - let module P = PrimitiveTactics in - let module T = Tacticals in let _,metasenv,_,_ = proof in let _,context,_ = CicUtil.lookup_meta goal metasenv in let termty,_ = - CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in - match termty with - (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]) - when LibraryObjects.is_eq_URI equri -> ( - match tty with - (C.MutInd (turi,typeno,exp_named_subst)) - | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) -> - - let consno2 = (* bruuutto: uso un eccezione per terminare con successo! buuu!! :-/ *) - try - let rec traverse t1 t2 = - match t1,t2 with - ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)), - (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))) - when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) -> - 0 - | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::applist1)), - (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::applist2))) - when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) -> - let rec traverse_list l1 l2 = - match l1,l2 with - [],[] -> 0 - | hd1::tl1,hd2::tl2 -> traverse hd1 hd2; traverse_list tl1 tl2 - | _ -> raise (ProofEngineTypes.Fail "Discriminate: i 2 termini hanno in testa lo stesso costruttore, ma applicato a un numero diverso di termini. possibile???") - in traverse_list applist1 applist2 - - | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)), - (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))) - | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)), - (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_))) - | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)), - (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))) - | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)), - (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_))) - when (consno1 <> consno2) || (exp_named_subst1 <> exp_named_subst2) -> - raise (TwoDifferentSubtermsFound consno2) - | _ -> raise (ProofEngineTypes.Fail "Discriminate: not a discriminable equality") - in traverse t1 t2 - with (TwoDifferentSubtermsFound consno2) -> consno2 - in - if consno2 = 0 - then raise (ProofEngineTypes.Fail "Discriminate: Discriminating terms are structurally equal") - else - - let pattern = - (* a list of "True" except for the element in position consno2 which is "False" *) - match fst(CicEnvironment.get_obj - CicUniv.empty_ugraph turi) with - C.InductiveDefinition (ind_type_list,_,nr_ind_params,_) -> - let _,_,_,constructor_list = (List.nth ind_type_list typeno) in - let false_constr_id,_ = List.nth constructor_list (consno2 - 1) in - List.map - (function (id,cty) -> - let red_ty = CicReduction.whd context cty in (* dubbio: e' corretto ridurre in questo context ??? *) - let rec aux t k = - match t with - C.Prod (_,_,target) when (k <= nr_ind_params) -> - aux target (k+1) - | C.Prod (binder,source,target) when (k > nr_ind_params) -> - C.Lambda (binder,source,(aux target (k+1))) - | _ -> - if (id = false_constr_id) - then (C.MutInd(LibraryObjects.false_URI (),0,[])) - else (C.MutInd(LibraryObjects.true_URI (),0,[])) - in aux red_ty 1 - ) - constructor_list - | _ -> raise (ProofEngineTypes.Fail "Discriminate: object is not an Inductive Definition: it's imposible") - in - - let (proof',goals') = - ProofEngineTypes.apply_tactic - (EliminationTactics.elim_type_tac - (C.MutInd(LibraryObjects.false_URI (),0,[]))) - status - in - (match goals' with - [goal'] -> - let _,metasenv',_,_ = proof' in - let _,context',gty' = - CicUtil.lookup_meta goal' metasenv' - in - ProofEngineTypes.apply_tactic - (T.then_ - ~start: - (ReductionTactics.change_tac - ~pattern:(ProofEngineTypes.conclusion_pattern - (Some gty')) - (fun _ m u -> C.Appl [ - C.Lambda ( - C.Name "x", tty, - C.MutCase ( - turi, typeno, - (C.Lambda ((C.Name "x"),tty,(C.Sort C.Prop))), - (C.Rel 1), pattern - ) - ); - t2], m, u)) - ~continuation: - ( - T.then_ - ~start: - (EqualityTactics.rewrite_simpl_tac - ~direction:`RightToLeft - ~pattern:(ProofEngineTypes.conclusion_pattern None) - term) - ~continuation:(IntroductionTactics.constructor_tac ~n:1) - )) - (proof',goal') - | _ -> raise (ProofEngineTypes.Fail "Discriminate: ElimType False left more (or less) than one goal") - ) - | _ -> raise (ProofEngineTypes.Fail "Discriminate: not a discriminable equality") - ) - | _ -> raise (ProofEngineTypes.Fail "Discriminate: not an equality") - in + CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph + in + match termty with + | (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]) + when LibraryObjects.is_eq_URI equri -> + let turi,typeno,exp_named_subst,left_args = + match tty with + | (C.MutInd (turi,typeno,exp_named_subst)) -> + turi,typeno,exp_named_subst,[] + | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::left_args)) -> + turi,typeno,exp_named_subst,left_args + | _ -> fail "not a discriminable equality" + in + let consno = + match find_discriminating_consno t1 t2 with + | Some consno -> consno + | None -> fail "discriminating terms are structurally equal" + in + let pattern = mk_pattern turi typeno consno context left_args in + let (proof',goals') = + ProofEngineTypes.apply_tactic + (EliminationTactics.elim_type_tac + (C.MutInd (LibraryObjects.false_URI (), 0, []))) + status + in + (match goals' with + | [goal'] -> + let _,metasenv',_,_ = proof' in + let _,context',gty' = CicUtil.lookup_meta goal' metasenv' in + ProofEngineTypes.apply_tactic + (T.then_ + ~start: + (ReductionTactics.change_tac + ~pattern:(ProofEngineTypes.conclusion_pattern (Some gty')) + (fun _ m u -> + C.Appl [ + C.Lambda ( C.Name "x", tty, + C.MutCase (turi, typeno, + (C.Lambda ((C.Name "x"), + (CicSubstitution.lift 1 tty), + (C.Sort C.Prop))), + (C.Rel 1), pattern)); + t2 ], m, u)) + ~continuation: + (T.then_ + ~start: + (EqualityTactics.rewrite_simpl_tac + ~direction:`RightToLeft + ~pattern:(ProofEngineTypes.conclusion_pattern None) + term) + ~continuation: + (IntroductionTactics.constructor_tac ~n:1))) + (proof',goal') + | [] -> fail "ElimType False left no goals" + | _ -> fail "ElimType False left more than one goal") + | _ -> fail "not an equality" + in ProofEngineTypes.mk_tactic (discriminate'_tac ~term) -;; let discriminate_tac ~term = let discriminate_tac ~term status = @@ -338,17 +338,11 @@ let discriminate_tac ~term = status in ProofEngineTypes.mk_tactic (discriminate_tac ~term) -;; - - let decide_equality_tac = (* il goal e' un termine della forma t1=t2\/~t1=t2; la tattica decide se l'uguaglianza e' vera o no e lo risolve *) Tacticals.id_tac -;; - - let compare_tac ~term = Tacticals.id_tac (* diff --git a/helm/ocaml/tactics/primitiveTactics.ml b/helm/ocaml/tactics/primitiveTactics.ml index 97f402052..62f4eb1f3 100644 --- a/helm/ocaml/tactics/primitiveTactics.ml +++ b/helm/ocaml/tactics/primitiveTactics.ml @@ -281,7 +281,8 @@ let apply_tac_verbose ~term (proof, goal) = in let metasenv' = metasenv@newmetasenvfragment in let termty,_ = - CicTypeChecker.type_of_aux' metasenv' context term' CicUniv.empty_ugraph in + CicTypeChecker.type_of_aux' metasenv' context term' CicUniv.empty_ugraph + in let termty = CicSubstitution.subst_vars exp_named_subst_diff termty in let goal_arity = count_prods context ty in @@ -304,7 +305,6 @@ let apply_tac_verbose ~term (proof, goal) = in let bo' = apply_subst t in let newmetasenv'' = new_uninstantiatedmetas@old_uninstantiatedmetas in -(* prerr_endline ("me: " ^ CicMetaSubst.ppmetasenv newmetasenv'' subst); *) let subst_in = (* if we just apply the subtitution, the type is irrelevant: we may use Implicit, since it will be dropped *) diff --git a/helm/ocaml/tactics/reductionTactics.ml b/helm/ocaml/tactics/reductionTactics.ml index 4abf2fb07..4fc192a5b 100644 --- a/helm/ocaml/tactics/reductionTactics.ml +++ b/helm/ocaml/tactics/reductionTactics.ml @@ -191,12 +191,13 @@ let change_tac ~pattern with_what = (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 metasenv' = + List.map + (function + | (n,_,_) when n = metano -> (metano,context',ty') + | _ as t -> t) + metasenv + in (curi,metasenv',pbo,pty), [metano] in mk_tactic (change_tac ~pattern ~with_what)