--- /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/.
+ *)
+
+(* $Id$ *)
+
+exception TheTypeOfTheCurrentGoalIsAMetaICannotChooseTheRightElimiantionPrinciple
+exception NotAnInductiveTypeToEliminate
+exception WrongUriToVariable of string
+exception NotAnEliminator
+
+module PET = ProofEngineTypes
+
+(* lambda_abstract newmeta ty *)
+(* returns a triple [bo],[context],[ty'] where *)
+(* [ty] = Pi/LetIn [context].[ty'] ([context] is a vector!) *)
+(* and [bo] = Lambda/LetIn [context].(Meta [newmeta]) *)
+(* So, lambda_abstract is the core of the implementation of *)
+(* the Intros tactic. *)
+(* howmany = -1 means Intros, howmany > 0 means Intros n *)
+let lambda_abstract ?(howmany=(-1)) metasenv context newmeta ty mk_fresh_name =
+ let module C = Cic in
+ let rec collect_context context howmany do_whd ty =
+ match howmany with
+ | 0 ->
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ context, ty, (C.Meta (newmeta,irl))
+ | _ ->
+ match ty with
+ C.Cast (te,_) -> collect_context context howmany do_whd te
+ | C.Prod (n,s,t) ->
+ let n' = mk_fresh_name metasenv context n ~typ:s in
+ let (context',ty,bo) =
+ let entry = match n' with
+ | C.Name _ -> Some (n',(C.Decl s))
+ | C.Anonymous -> None
+ in
+ let ctx = entry :: context in
+ collect_context ctx (howmany - 1) do_whd t
+ in
+ (context',ty,C.Lambda(n',s,bo))
+ | C.LetIn (n,s,sty,t) ->
+ let (context',ty,bo) =
+ collect_context ((Some (n,(C.Def (s,sty))))::context) (howmany - 1) do_whd t
+ in
+ (context',ty,C.LetIn(n,s,sty,bo))
+ | _ as t ->
+ if howmany <= 0 then
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ context, t, (C.Meta (newmeta,irl))
+ else if do_whd then
+ let t = CicReduction.whd ~delta:true context t in
+ collect_context context howmany false t
+ else
+ raise (PET.Fail (lazy "intro(s): not enough products or let-ins"))
+ in
+ collect_context context howmany true ty
+
+let eta_expand metasenv context t arg =
+ let module T = CicTypeChecker in
+ let module S = CicSubstitution in
+ let module C = Cic in
+ let rec aux n =
+ function
+ t' when t' = S.lift n arg -> C.Rel (1 + n)
+ | C.Rel m -> if m <= n then C.Rel m else C.Rel (m+1)
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst' = aux_exp_named_subst n exp_named_subst in
+ C.Var (uri,exp_named_subst')
+ | C.Meta (i,l) ->
+ let l' =
+ List.map (function None -> None | Some t -> Some (aux n t)) l
+ in
+ C.Meta (i, l')
+ | C.Sort _
+ | C.Implicit _ as t -> t
+ | C.Cast (te,ty) -> C.Cast (aux n te, aux n ty)
+ | C.Prod (nn,s,t) -> C.Prod (nn, aux n s, aux (n+1) t)
+ | C.Lambda (nn,s,t) -> C.Lambda (nn, aux n s, aux (n+1) t)
+ | C.LetIn (nn,s,ty,t) -> C.LetIn (nn, aux n s, aux n ty, aux (n+1) t)
+ | C.Appl l -> C.Appl (List.map (aux n) l)
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst' = aux_exp_named_subst n exp_named_subst in
+ C.Const (uri,exp_named_subst')
+ | C.MutInd (uri,i,exp_named_subst) ->
+ let exp_named_subst' = aux_exp_named_subst n exp_named_subst in
+ C.MutInd (uri,i,exp_named_subst')
+ | C.MutConstruct (uri,i,j,exp_named_subst) ->
+ let exp_named_subst' = aux_exp_named_subst n exp_named_subst in
+ C.MutConstruct (uri,i,j,exp_named_subst')
+ | C.MutCase (sp,i,outt,t,pl) ->
+ C.MutCase (sp,i,aux n outt, aux n t,
+ List.map (aux n) pl)
+ | C.Fix (i,fl) ->
+ let tylen = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,i,ty,bo) -> (name, i, aux n ty, aux (n+tylen) bo))
+ fl
+ in
+ C.Fix (i, substitutedfl)
+ | C.CoFix (i,fl) ->
+ let tylen = List.length fl in
+ let substitutedfl =
+ List.map
+ (fun (name,ty,bo) -> (name, aux n ty, aux (n+tylen) bo))
+ fl
+ in
+ C.CoFix (i, substitutedfl)
+ and aux_exp_named_subst n =
+ List.map (function uri,t -> uri,aux n t)
+ in
+ let argty,_ =
+ T.type_of_aux' metasenv context arg CicUniv.empty_ugraph (* TASSI: FIXME *)
+ in
+ let fresh_name =
+ FreshNamesGenerator.mk_fresh_name ~subst:[]
+ metasenv context (Cic.Name "Heta") ~typ:argty
+ in
+ (C.Appl [C.Lambda (fresh_name,argty,aux 0 t) ; arg])
+
+(*CSC: ma serve solamente la prima delle new_uninst e l'unione delle due!!! *)
+let classify_metas newmeta in_subst_domain subst_in metasenv =
+ List.fold_right
+ (fun (i,canonical_context,ty) (old_uninst,new_uninst) ->
+ if in_subst_domain i then
+ old_uninst,new_uninst
+ else
+ let ty' = subst_in canonical_context ty in
+ let canonical_context' =
+ List.fold_right
+ (fun entry canonical_context' ->
+ let entry' =
+ match entry with
+ Some (n,Cic.Decl s) ->
+ Some (n,Cic.Decl (subst_in canonical_context' s))
+ | None -> None
+ | Some (n,Cic.Def (bo,ty)) ->
+ Some
+ (n,
+ Cic.Def
+ (subst_in canonical_context' bo,
+ subst_in canonical_context' ty))
+ in
+ entry'::canonical_context'
+ ) canonical_context []
+ in
+ if i < newmeta then
+ ((i,canonical_context',ty')::old_uninst),new_uninst
+ else
+ old_uninst,((i,canonical_context',ty')::new_uninst)
+ ) metasenv ([],[])
+
+(* Useful only inside apply_tac *)
+let
+ generalize_exp_named_subst_with_fresh_metas context newmeta uri exp_named_subst
+=
+ let module C = Cic in
+ let params =
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ CicUtil.params_of_obj o
+ in
+ let exp_named_subst_diff,new_fresh_meta,newmetasenvfragment,exp_named_subst'=
+ let next_fresh_meta = ref newmeta in
+ let newmetasenvfragment = ref [] in
+ let exp_named_subst_diff = ref [] in
+ let rec aux =
+ function
+ [],[] -> []
+ | uri::tl,[] ->
+ let ty =
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ match o with
+ C.Variable (_,_,ty,_,_) ->
+ CicSubstitution.subst_vars !exp_named_subst_diff ty
+ | _ -> raise (WrongUriToVariable (UriManager.string_of_uri uri))
+ in
+(* CSC: patch to generate ?1 : ?2 : Type in place of ?1 : Type to simulate ?1 :< Type
+ (match ty with
+ C.Sort (C.Type _) as s -> (* TASSI: ?? *)
+ let fresh_meta = !next_fresh_meta in
+ let fresh_meta' = fresh_meta + 1 in
+ next_fresh_meta := !next_fresh_meta + 2 ;
+ let subst_item = uri,C.Meta (fresh_meta',[]) in
+ newmetasenvfragment :=
+ (fresh_meta,[],C.Sort (C.Type (CicUniv.fresh()))) ::
+ (* TASSI: ?? *)
+ (fresh_meta',[],C.Meta (fresh_meta,[])) :: !newmetasenvfragment ;
+ exp_named_subst_diff := !exp_named_subst_diff @ [subst_item] ;
+ subst_item::(aux (tl,[]))
+ | _ ->
+*)
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ let subst_item = uri,C.Meta (!next_fresh_meta,irl) in
+ newmetasenvfragment :=
+ (!next_fresh_meta,context,ty)::!newmetasenvfragment ;
+ exp_named_subst_diff := !exp_named_subst_diff @ [subst_item] ;
+ incr next_fresh_meta ;
+ subst_item::(aux (tl,[]))(*)*)
+ | uri::tl1,((uri',_) as s)::tl2 ->
+ assert (UriManager.eq uri uri') ;
+ s::(aux (tl1,tl2))
+ | [],_ -> assert false
+ in
+ let exp_named_subst' = aux (params,exp_named_subst) in
+ !exp_named_subst_diff,!next_fresh_meta,
+ List.rev !newmetasenvfragment, exp_named_subst'
+ in
+ new_fresh_meta,newmetasenvfragment,exp_named_subst',exp_named_subst_diff
+;;
+
+let new_metasenv_and_unify_and_t newmeta' metasenv' subst context term' ty termty goal_arity =
+ let (consthead,newmetasenv,arguments,_) =
+ TermUtil.saturate_term newmeta' metasenv' context termty
+ goal_arity in
+ let subst,newmetasenv',_ =
+ CicUnification.fo_unif_subst
+ subst context newmetasenv consthead ty CicUniv.empty_ugraph
+ in
+ let t =
+ if List.length arguments = 0 then term' else Cic.Appl (term'::arguments)
+ in
+ subst,newmetasenv',t
+
+let rec count_prods context ty =
+ match CicReduction.whd context ty with
+ Cic.Prod (n,s,t) -> 1 + count_prods (Some (n,Cic.Decl s)::context) t
+ | _ -> 0
+
+let apply_with_subst ~term ~subst ~maxmeta (proof, goal) =
+ (* Assumption: The term "term" must be closed in the current context *)
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let module C = Cic in
+ let (_,metasenv,_subst,_,_, _) = proof in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ let newmeta = max (CicMkImplicit.new_meta metasenv subst) maxmeta in
+ let exp_named_subst_diff,newmeta',newmetasenvfragment,term' =
+ match term with
+ C.Var (uri,exp_named_subst) ->
+ let newmeta',newmetasenvfragment,exp_named_subst',exp_named_subst_diff =
+ generalize_exp_named_subst_with_fresh_metas context newmeta uri
+ exp_named_subst
+ in
+ exp_named_subst_diff,newmeta',newmetasenvfragment,
+ C.Var (uri,exp_named_subst')
+ | C.Const (uri,exp_named_subst) ->
+ let newmeta',newmetasenvfragment,exp_named_subst',exp_named_subst_diff =
+ generalize_exp_named_subst_with_fresh_metas context newmeta uri
+ exp_named_subst
+ in
+ exp_named_subst_diff,newmeta',newmetasenvfragment,
+ C.Const (uri,exp_named_subst')
+ | C.MutInd (uri,tyno,exp_named_subst) ->
+ let newmeta',newmetasenvfragment,exp_named_subst',exp_named_subst_diff =
+ generalize_exp_named_subst_with_fresh_metas context newmeta uri
+ exp_named_subst
+ in
+ exp_named_subst_diff,newmeta',newmetasenvfragment,
+ C.MutInd (uri,tyno,exp_named_subst')
+ | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
+ let newmeta',newmetasenvfragment,exp_named_subst',exp_named_subst_diff =
+ generalize_exp_named_subst_with_fresh_metas context newmeta uri
+ exp_named_subst
+ in
+ exp_named_subst_diff,newmeta',newmetasenvfragment,
+ C.MutConstruct (uri,tyno,consno,exp_named_subst')
+ | _ -> [],newmeta,[],term
+ in
+ let metasenv' = metasenv@newmetasenvfragment in
+ let termty,_ =
+ 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
+ let subst,newmetasenv',t =
+ let rec add_one_argument n =
+ try
+ new_metasenv_and_unify_and_t newmeta' metasenv' subst context term' ty
+ termty n
+ with CicUnification.UnificationFailure _ when n > 0 ->
+ add_one_argument (n - 1)
+ in
+ add_one_argument goal_arity
+ in
+ let in_subst_domain i = List.exists (function (j,_) -> i=j) subst in
+ let apply_subst = CicMetaSubst.apply_subst subst in
+ let old_uninstantiatedmetas,new_uninstantiatedmetas =
+ (* subst_in doesn't need the context. Hence the underscore. *)
+ let subst_in _ = CicMetaSubst.apply_subst subst in
+ classify_metas newmeta in_subst_domain subst_in newmetasenv'
+ in
+ let bo' = apply_subst t in
+ let newmetasenv'' = new_uninstantiatedmetas@old_uninstantiatedmetas in
+ let subst_in =
+ (* if we just apply the subtitution, the type is irrelevant:
+ we may use Implicit, since it will be dropped *)
+ ((metano,(context,bo',Cic.Implicit None))::subst)
+ in
+ let (newproof, newmetasenv''') =
+ ProofEngineHelpers.subst_meta_and_metasenv_in_proof proof metano subst_in
+ newmetasenv''
+ in
+ let subst = ((metano,(context,bo',ty))::subst) in
+ subst,
+ (newproof, List.map (function (i,_,_) -> i) new_uninstantiatedmetas),
+ max maxmeta (CicMkImplicit.new_meta newmetasenv''' subst)
+
+
+(* ALB *)
+let apply_with_subst ~term ?(subst=[]) ?(maxmeta=0) status =
+ try
+(* apply_tac_verbose ~term status *)
+ apply_with_subst ~term ~subst ~maxmeta status
+ (* TODO cacciare anche altre eccezioni? *)
+ with
+ | CicUnification.UnificationFailure msg
+ | CicTypeChecker.TypeCheckerFailure msg -> raise (PET.Fail msg)
+
+(* ALB *)
+let apply_tac_verbose ~term status =
+ let subst, status, _ = apply_with_subst ~term status in
+ (CicMetaSubst.apply_subst subst), status
+
+let apply_tac ~term status = snd (apply_tac_verbose ~term status)
+
+ (* TODO per implementare i tatticali e' necessario che tutte le tattiche
+ sollevino _solamente_ Fail *)
+let apply_tac ~term =
+ let apply_tac ~term status =
+ try
+ apply_tac ~term status
+ (* TODO cacciare anche altre eccezioni? *)
+ with
+ | CicUnification.UnificationFailure msg
+ | CicTypeChecker.TypeCheckerFailure msg ->
+ raise (PET.Fail msg)
+ in
+ PET.mk_tactic (apply_tac ~term)
+
+let intros_tac ?howmany ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[]) ()=
+ let intros_tac (proof, goal)
+ =
+ let module C = Cic in
+ let module R = CicReduction in
+ let (_,metasenv,_subst,_,_, _) = proof in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ let newmeta = ProofEngineHelpers.new_meta_of_proof ~proof in
+ let (context',ty',bo') =
+ lambda_abstract ?howmany metasenv context newmeta ty mk_fresh_name_callback
+ in
+ let (newproof, _) =
+ ProofEngineHelpers.subst_meta_in_proof proof metano bo'
+ [newmeta,context',ty']
+ in
+ (newproof, [newmeta])
+ in
+ PET.mk_tactic intros_tac
+
+let cut_tac ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[]) term =
+ let cut_tac
+ ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
+ term (proof, goal)
+ =
+ let module C = Cic in
+ let curi,metasenv,_subst,pbo,pty, attrs = proof in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ let newmeta1 = ProofEngineHelpers.new_meta_of_proof ~proof in
+ let newmeta2 = newmeta1 + 1 in
+ let fresh_name =
+ mk_fresh_name_callback metasenv context (Cic.Name "Hcut") ~typ:term in
+ let context_for_newmeta1 =
+ (Some (fresh_name,C.Decl term))::context in
+ let irl1 =
+ CicMkImplicit.identity_relocation_list_for_metavariable
+ context_for_newmeta1
+ in
+ let irl2 =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ let newmeta1ty = CicSubstitution.lift 1 ty in
+ let bo' =
+ Cic.LetIn (fresh_name, C.Meta (newmeta2,irl2), term, C.Meta (newmeta1,irl1))
+ in
+ let (newproof, _) =
+ ProofEngineHelpers.subst_meta_in_proof proof metano bo'
+ [newmeta2,context,term; newmeta1,context_for_newmeta1,newmeta1ty];
+ in
+ (newproof, [newmeta1 ; newmeta2])
+ in
+ PET.mk_tactic (cut_tac ~mk_fresh_name_callback term)
+
+let letin_tac ?(mk_fresh_name_callback=FreshNamesGenerator.mk_fresh_name ~subst:[]) term =
+ let letin_tac
+ ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
+ term (proof, goal)
+ =
+ let module C = Cic in
+ let curi,metasenv,_subst,pbo,pty, attrs = proof in
+ (* occur check *)
+ let occur i t =
+ let m = CicUtil.metas_of_term t in
+ List.exists (fun (j,_) -> i=j) m
+ in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ if occur metano term then
+ raise
+ (ProofEngineTypes.Fail (lazy
+ "You can't letin a term containing the current goal"));
+ let tty,_ =
+ CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+ let newmeta = ProofEngineHelpers.new_meta_of_proof ~proof in
+ let fresh_name =
+ mk_fresh_name_callback metasenv context (Cic.Name "Hletin") ~typ:term in
+ let context_for_newmeta =
+ (Some (fresh_name,C.Def (term,tty)))::context in
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable
+ context_for_newmeta
+ in
+ let newmetaty = CicSubstitution.lift 1 ty in
+ let bo' = C.LetIn (fresh_name,term,tty,C.Meta (newmeta,irl)) in
+ let (newproof, _) =
+ ProofEngineHelpers.subst_meta_in_proof
+ proof metano bo'[newmeta,context_for_newmeta,newmetaty]
+ in
+ (newproof, [newmeta])
+ in
+ PET.mk_tactic (letin_tac ~mk_fresh_name_callback term)
+
+ (** functional part of the "exact" tactic *)
+let exact_tac ~term =
+ let exact_tac ~term (proof, goal) =
+ (* Assumption: the term bo must be closed in the current context *)
+ let (_,metasenv,_subst,_,_, _) = proof in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let ty_term,u = T.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+ let b,_ = R.are_convertible context ty_term ty u in (* TASSI: FIXME *)
+ if b then
+ begin
+ let (newproof, metasenv') =
+ ProofEngineHelpers.subst_meta_in_proof proof metano term [] in
+ (newproof, [])
+ end
+ else
+ raise (PET.Fail (lazy "The type of the provided term is not the one expected."))
+ in
+ PET.mk_tactic (exact_tac ~term)
+
+(* not really "primitive" tactics .... *)
+
+module TC = CicTypeChecker
+module UM = UriManager
+module R = CicReduction
+module C = Cic
+module PEH = ProofEngineHelpers
+module PER = ProofEngineReduction
+module MS = CicMetaSubst
+module S = CicSubstitution
+module T = Tacticals
+module RT = ReductionTactics
+
+let rec args_init n f =
+ if n <= 0 then [] else f n :: args_init (pred n) f
+
+let mk_predicate_for_elim
+ ~context ~metasenv ~ugraph ~goal ~arg ~using ~cpattern ~args_no =
+ let instantiated_eliminator =
+ let f n = if n = 1 then arg else C.Implicit None in
+ C.Appl (using :: args_init args_no f)
+ in
+ let _actual_arg, iety, _metasenv', _ugraph =
+ CicRefine.type_of_aux' metasenv context instantiated_eliminator ugraph
+ in
+ let _actual_meta, actual_args = match iety with
+ | C.Meta (i, _) -> i, []
+ | C.Appl (C.Meta (i, _) :: args) -> i, args
+ | _ -> assert false
+ in
+(* let _, upto = PEH.split_with_whd (List.nth splits pred_pos) in *)
+ let rec mk_pred metasenv context' pred arg' cpattern' = function
+ | [] -> metasenv, pred, arg'
+ | arg :: tail ->
+(* FG: we find the predicate for the eliminator as in the rewrite tactic ****)
+ let argty, _ugraph = TC.type_of_aux' metasenv context arg ugraph in
+ let argty = CicReduction.whd context argty in
+ let fresh_name =
+ FreshNamesGenerator.mk_fresh_name
+ ~subst:[] metasenv context' C.Anonymous ~typ:argty
+ in
+ let hyp = Some (fresh_name, C.Decl argty) in
+ let lazy_term c m u =
+ let distance = List.length c - List.length context in
+ S.lift distance arg, m, u
+ in
+ let pattern = Some lazy_term, [], Some cpattern' in
+ let subst, metasenv, _ugraph, _conjecture, selected_terms =
+ ProofEngineHelpers.select
+ ~metasenv ~ugraph ~conjecture:(0, context, pred) ~pattern
+ in
+ let metasenv = MS.apply_subst_metasenv subst metasenv in
+ let map (_context_of_t, t) l = t :: l in
+ let what = List.fold_right map selected_terms [] in
+ let arg' = MS.apply_subst subst arg' in
+ let argty = MS.apply_subst subst argty in
+ let pred = PER.replace_with_rel_1_from ~equality:(==) ~what 1 pred in
+ let pred = MS.apply_subst subst pred in
+ let pred = C.Lambda (fresh_name, argty, pred) in
+ let cpattern' = C.Lambda (C.Anonymous, C.Implicit None, cpattern') in
+ mk_pred metasenv (hyp :: context') pred arg' cpattern' tail
+ in
+ let metasenv, pred, arg =
+ mk_pred metasenv context goal arg cpattern (List.rev actual_args)
+ in
+ HLog.debug ("PREDICATE: " ^ CicPp.ppterm ~metasenv pred ^ " ARGS: " ^ String.concat " " (List.map (CicPp.ppterm ~metasenv) actual_args));
+ metasenv, pred, arg, actual_args
+
+let beta_after_elim_tac upto predicate =
+ let beta_after_elim_tac status =
+ let proof, goal = status in
+ let _, metasenv, _subst, _, _, _ = proof in
+ let _, _, ty = CicUtil.lookup_meta goal metasenv in
+ let mk_pattern ~equality ~upto ~predicate ty =
+ (* code adapted from ProceduralConversion.generalize *)
+ let meta = C.Implicit None in
+ let hole = C.Implicit (Some `Hole) in
+ let anon = C.Anonymous in
+ let is_meta =
+ let map b = function
+ | C.Implicit None when b -> b
+ | _ -> false
+ in
+ List.fold_left map true
+ in
+ let rec gen_fix len k (name, i, ty, bo) =
+ name, i, gen_term k ty, gen_term (k + len) bo
+ and gen_cofix len k (name, ty, bo) =
+ name, gen_term k ty, gen_term (k + len) bo
+ and gen_term k = function
+ | C.Sort _
+ | C.Implicit _
+ | C.Const (_, _)
+ | C.Var (_, _)
+ | C.MutInd (_, _, _)
+ | C.MutConstruct (_, _, _, _)
+ | C.Meta (_, _)
+ | C.Rel _ -> meta
+ | C.Appl (hd :: tl) when equality hd (S.lift k predicate) ->
+ assert (List.length tl = upto);
+ hole
+ | C.Appl ts ->
+ let ts = List.map (gen_term k) ts in
+ if is_meta ts then meta else C.Appl ts
+ | C.Cast (te, ty) ->
+ let te, ty = gen_term k te, gen_term k ty in
+ if is_meta [te; ty] then meta else C.Cast (te, ty)
+ | C.MutCase (sp, i, outty, t, pl) ->
+ let outty, t, pl = gen_term k outty, gen_term k t, List.map (gen_term k) pl in
+ if is_meta (outty :: t :: pl) then meta else hole (* C.MutCase (sp, i, outty, t, pl) *)
+ | C.Prod (_, s, t) ->
+ let s, t = gen_term k s, gen_term (succ k) t in
+ if is_meta [s; t] then meta else C.Prod (anon, s, t)
+ | C.Lambda (_, s, t) ->
+ let s, t = gen_term k s, gen_term (succ k) t in
+ if is_meta [s; t] then meta else C.Lambda (anon, s, t)
+ | C.LetIn (_, s, ty, t) ->
+ let s,ty,t = gen_term k s, gen_term k ty, gen_term (succ k) t in
+ if is_meta [s; t] then meta else C.LetIn (anon, s, ty, t)
+ | C.Fix (i, fl) -> C.Fix (i, List.map (gen_fix (List.length fl) k) fl)
+ | C.CoFix (i, fl) -> C.CoFix (i, List.map (gen_cofix (List.length fl) k) fl)
+ in
+ None, [], Some (gen_term 0 ty)
+ in
+ let equality = CicUtil.alpha_equivalence in
+ let pattern = mk_pattern ~equality ~upto ~predicate ty in
+ let tactic = RT.head_beta_reduce_tac ~delta:false ~upto ~pattern in
+ PET.apply_tactic tactic status
+ in
+ PET.mk_tactic beta_after_elim_tac
+
+let elim_tac ?using ?(pattern = PET.conclusion_pattern None) term =
+ let elim_tac (proof, goal) =
+ let cpattern = match pattern with
+ | None, [], Some cpattern -> cpattern
+ | _ -> raise (PET.Fail (lazy "not implemented"))
+ in
+ let ugraph = CicUniv.empty_ugraph in
+ let curi, metasenv, _subst, proofbo, proofty, attrs = proof in
+ let conjecture = CicUtil.lookup_meta goal metasenv in
+ let metano, context, ty = conjecture in
+ let termty,_ugraph = TC.type_of_aux' metasenv context term ugraph in
+ let termty = CicReduction.whd context termty in
+ let termty, metasenv', arguments, _fresh_meta =
+ TermUtil.saturate_term
+ (ProofEngineHelpers.new_meta_of_proof proof) metasenv context termty 0 in
+ let term = if arguments = [] then term else Cic.Appl (term::arguments) in
+ let uri, exp_named_subst, typeno, _args =
+ match termty with
+ C.MutInd (uri,typeno,exp_named_subst) -> (uri,exp_named_subst,typeno,[])
+ | C.Appl ((C.MutInd (uri,typeno,exp_named_subst))::args) ->
+ (uri,exp_named_subst,typeno,args)
+ | _ -> raise NotAnInductiveTypeToEliminate
+ in
+ let eliminator_uri =
+ let buri = UM.buri_of_uri uri in
+ let name =
+ let o,_ugraph = CicEnvironment.get_obj ugraph uri in
+ match o with
+ C.InductiveDefinition (tys,_,_,_) ->
+ let (name,_,_,_) = List.nth tys typeno in
+ name
+ | _ -> assert false
+ in
+ let ty_ty,_ugraph = TC.type_of_aux' metasenv' context ty ugraph in
+ let ext =
+ match ty_ty with
+ C.Sort C.Prop -> "_ind"
+ | C.Sort C.Set -> "_rec"
+ | C.Sort C.CProp -> "_rec"
+ | C.Sort (C.Type _)-> "_rect"
+ | C.Meta (_,_) -> raise TheTypeOfTheCurrentGoalIsAMetaICannotChooseTheRightElimiantionPrinciple
+ | _ -> assert false
+ in
+ UM.uri_of_string (buri ^ "/" ^ name ^ ext ^ ".con")
+ in
+ let eliminator_ref = match using with
+ | None -> C.Const (eliminator_uri, exp_named_subst)
+ | Some t -> t
+ in
+ let ety, _ugraph =
+ TC.type_of_aux' metasenv' context eliminator_ref ugraph in
+(* FG: ADDED PART ***********************************************************)
+(* FG: we can not assume eliminator is the default eliminator ***************)
+ let splits, args_no = PEH.split_with_whd (context, ety) in
+ let pred_pos = match List.hd splits with
+ | _, C.Rel i when i > 1 && i <= args_no -> i
+ | _, C.Appl (C.Rel i :: _) when i > 1 && i <= args_no -> i
+ | _ -> raise NotAnEliminator
+ in
+ let metasenv', pred, term, actual_args = match pattern with
+ | None, [], Some (C.Implicit (Some `Hole)) ->
+ metasenv', C.Implicit None, term, []
+ | _ ->
+ mk_predicate_for_elim
+ ~args_no ~context ~ugraph ~cpattern
+ ~metasenv:metasenv' ~arg:term ~using:eliminator_ref ~goal:ty
+ in
+(* FG: END OF ADDED PART ****************************************************)
+ let term_to_refine =
+ let f n =
+ if n = pred_pos then pred else
+ if n = 1 then term else C.Implicit None
+ in
+ C.Appl (eliminator_ref :: args_init args_no f)
+ in
+ let refined_term,_refined_termty,metasenv'',_ugraph =
+ CicRefine.type_of_aux' metasenv' context term_to_refine ugraph
+ in
+ let new_goals =
+ ProofEngineHelpers.compare_metasenvs
+ ~oldmetasenv:metasenv ~newmetasenv:metasenv''
+ in
+ let proof' = curi,metasenv'',_subst,proofbo,proofty, attrs in
+ let proof'', new_goals' =
+ PET.apply_tactic (apply_tac ~term:refined_term) (proof',goal)
+ in
+ (* The apply_tactic can have closed some of the new_goals *)
+ let patched_new_goals =
+ let (_,metasenv''',_subst,_,_, _) = proof'' in
+ List.filter
+ (function i -> List.exists (function (j,_,_) -> j=i) metasenv''')
+ new_goals @ new_goals'
+ in
+ let res = proof'', patched_new_goals in
+ let upto = List.length actual_args in
+ if upto = 0 then res else
+ let continuation = beta_after_elim_tac upto pred in
+ let dummy_status = proof,goal in
+ PET.apply_tactic
+ (T.then_ ~start:(PET.mk_tactic (fun _ -> res)) ~continuation)
+ dummy_status
+ in
+ PET.mk_tactic elim_tac
+;;
+
+let cases_intros_tac ?(howmany=(-1)) ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[]) term =
+ let cases_tac ~term (proof, goal) =
+ let module TC = CicTypeChecker in
+ let module U = UriManager in
+ let module R = CicReduction in
+ let module C = Cic in
+ let (curi,metasenv,_subst, proofbo,proofty, attrs) = proof in
+ let metano,context,ty = CicUtil.lookup_meta goal metasenv in
+ let termty,_ = TC.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+ let termty = CicReduction.whd context termty in
+ let (termty,metasenv',arguments,fresh_meta) =
+ TermUtil.saturate_term
+ (ProofEngineHelpers.new_meta_of_proof proof) metasenv context termty 0 in
+ let term = if arguments = [] then term else Cic.Appl (term::arguments) in
+ let uri,exp_named_subst,typeno,args =
+ match termty with
+ | C.MutInd (uri,typeno,exp_named_subst) -> (uri,exp_named_subst,typeno,[])
+ | C.Appl ((C.MutInd (uri,typeno,exp_named_subst))::args) ->
+ (uri,exp_named_subst,typeno,args)
+ | _ -> raise NotAnInductiveTypeToEliminate
+ in
+ let paramsno,itty,patterns,right_args =
+ match CicEnvironment.get_obj CicUniv.empty_ugraph uri with
+ | C.InductiveDefinition (tys,_,paramsno,_),_ ->
+ let _,left_parameters,right_args =
+ List.fold_right
+ (fun x (n,acc1,acc2) ->
+ if n > 0 then (n-1,acc1,x::acc2) else (n,x::acc1,acc2))
+ args (List.length args - paramsno, [],[])
+ in
+ let _,_,itty,cl = List.nth tys typeno in
+ let rec aux left_parameters context t =
+ match left_parameters,CicReduction.whd context t with
+ | [],C.Prod (name,source,target) ->
+ let fresh_name =
+ mk_fresh_name_callback metasenv' context name ~typ:source
+ in
+ C.Lambda (fresh_name,C.Implicit None,
+ aux [] (Some (fresh_name,C.Decl source)::context) target)
+ | hd::tl,C.Prod (name,source,target) ->
+ (* left parameters instantiation *)
+ aux tl context (CicSubstitution.subst hd target)
+ | [],_ -> C.Implicit None
+ | _ -> assert false
+ in
+ paramsno,itty,
+ List.map (function (_,cty) -> aux left_parameters context cty) cl,
+ right_args
+ | _ -> assert false
+ in
+ let outtype =
+ let n_right_args = List.length right_args in
+ let n_lambdas = n_right_args + 1 in
+ let lifted_ty = CicSubstitution.lift n_lambdas ty in
+ let captured_ty =
+ let what =
+ List.map (CicSubstitution.lift n_lambdas) (right_args)
+ in
+ let with_what meta =
+ let rec mkargs = function
+ | 0 -> assert false
+ | 1 -> []
+ | n ->
+ (if meta then Cic.Implicit None else Cic.Rel n)::(mkargs (n-1))
+ in
+ mkargs n_lambdas
+ in
+ let replaced = ref false in
+ let replace = ProofEngineReduction.replace_lifting
+ ~equality:(fun _ a b -> let rc = CicUtil.alpha_equivalence a b in
+ if rc then replaced := true; rc)
+ ~context:[]
+ in
+ let captured =
+ replace ~what:[CicSubstitution.lift n_lambdas term]
+ ~with_what:[Cic.Rel 1] ~where:lifted_ty
+ in
+ if not !replaced then
+ (* this means the matched term is not there,
+ * but maybe right params are: we user rels (to right args lambdas) *)
+ replace ~what ~with_what:(with_what false) ~where:captured
+ else
+ (* since the matched is there, rights should be inferrable *)
+ replace ~what ~with_what:(with_what true) ~where:captured
+ in
+ let captured_term_ty =
+ let term_ty = CicSubstitution.lift n_right_args termty in
+ let rec mkrels = function 0 -> []|n -> (Cic.Rel n)::(mkrels (n-1)) in
+ let rec fstn acc l n =
+ if n = 0 then acc else fstn (acc@[List.hd l]) (List.tl l) (n-1)
+ in
+ match term_ty with
+ | C.MutInd _ -> term_ty
+ | C.Appl ((C.MutInd (a,b,c))::args) ->
+ C.Appl ((C.MutInd (a,b,c))::
+ fstn [] args paramsno @ mkrels n_right_args)
+ | _ -> raise NotAnInductiveTypeToEliminate
+ in
+ let rec add_lambdas = function
+ | 0 -> captured_ty
+ | 1 ->
+ C.Lambda (C.Name "matched", captured_term_ty, (add_lambdas 0))
+ | n ->
+ C.Lambda (C.Name ("right_"^(string_of_int (n-1))),
+ C.Implicit None, (add_lambdas (n-1)))
+ in
+ add_lambdas n_lambdas
+ in
+ let term_to_refine = C.MutCase (uri,typeno,outtype,term,patterns) in
+ let refined_term,_,metasenv'',_ =
+ CicRefine.type_of_aux' metasenv' context term_to_refine
+ CicUniv.empty_ugraph
+ in
+ let new_goals =
+ ProofEngineHelpers.compare_metasenvs
+ ~oldmetasenv:metasenv ~newmetasenv:metasenv''
+ in
+ let proof' = curi,metasenv'',_subst,proofbo,proofty, attrs in
+ let proof'', new_goals' =
+ PET.apply_tactic (apply_tac ~term:refined_term) (proof',goal)
+ in
+ (* The apply_tactic can have closed some of the new_goals *)
+ let patched_new_goals =
+ let (_,metasenv''',_subst,_,_,_) = proof'' in
+ List.filter
+ (function i -> List.exists (function (j,_,_) -> j=i) metasenv''')
+ new_goals @ new_goals'
+ in
+ proof'', patched_new_goals
+ in
+ PET.mk_tactic (cases_tac ~term)
+;;
+
+
+let elim_intros_tac ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
+ ?depth ?using ?pattern what =
+ Tacticals.then_ ~start:(elim_tac ?using ?pattern what)
+ ~continuation:(intros_tac ~mk_fresh_name_callback ?howmany:depth ())
+;;
+
+(* The simplification is performed only on the conclusion *)
+let elim_intros_simpl_tac ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
+ ?depth ?using ?pattern what =
+ Tacticals.then_ ~start:(elim_tac ?using ?pattern what)
+ ~continuation:
+ (Tacticals.thens
+ ~start:(intros_tac ~mk_fresh_name_callback ?howmany:depth ())
+ ~continuations:
+ [ReductionTactics.simpl_tac
+ ~pattern:(ProofEngineTypes.conclusion_pattern None)])
+;;