--- /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/.
+ *)
+
+(* $Id$ *)
+
+module C = Cic
+module U = UriManager
+module P = PrimitiveTactics
+module T = Tacticals
+module CR = CicReduction
+module PST = ProofEngineStructuralRules
+module PET = ProofEngineTypes
+module CTC = CicTypeChecker
+module CU = CicUniv
+module S = CicSubstitution
+module RT = ReductionTactics
+module PEH = ProofEngineHelpers
+module ET = EqualityTactics
+module DTI = DoubleTypeInference
+
+let debug = false
+let debug_print =
+ if debug then (fun x -> prerr_endline (Lazy.force x)) else (fun _ -> ())
+
+(* term ha tipo t1=t2; funziona solo se t1 e t2 hanno in testa costruttori
+diversi *)
+
+let discriminate_tac ~term =
+ let true_URI =
+ match LibraryObjects.true_URI () with
+ Some uri -> uri
+ | None -> raise (PET.Fail (lazy "You need to register the default \"true\" definition first. Please use the \"default\" command")) in
+ let false_URI =
+ match LibraryObjects.false_URI () with
+ Some uri -> uri
+ | None -> raise (PET.Fail (lazy "You need to register the default \"false\" definition first. Please use the \"default\" command")) in
+ let fail msg = raise (PET.Fail (lazy ("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_branches_and_outtype turi typeno consno context args =
+ (* a list of "True" except for the element in position consno which
+ * is "False" *)
+ match fst (CicEnvironment.get_obj CU.empty_ugraph turi) with
+ | C.InductiveDefinition (ind_type_list,_,paramsno,_) ->
+ let _,_,rty,constructor_list = List.nth ind_type_list typeno in
+ let false_constr_id,_ = List.nth constructor_list (consno - 1) in
+ let branches =
+ List.map
+ (fun (id,cty) ->
+ (* dubbio: e' corretto ridurre in questo context ??? *)
+ let red_ty = CR.whd context cty in
+ let rec aux t k =
+ match t with
+ | C.Prod (_,_,target) when (k <= paramsno) ->
+ S.subst (List.nth args (k-1))
+ (aux target (k+1))
+ | C.Prod (binder,source,target) when (k > paramsno) ->
+ C.Lambda (binder, source, (aux target (k+1)))
+ | _ ->
+ if (id = false_constr_id)
+ then (C.MutInd(false_URI,0,[]))
+ else (C.MutInd(true_URI,0,[]))
+ in
+ (S.lift 1 (aux red_ty 1)))
+ constructor_list in
+ let outtype =
+ let seed = ref 0 in
+ let rec mk_lambdas rev_left_args =
+ function
+ 0, args, C.Prod (_,so,ta) ->
+ C.Lambda
+ (C.Name (incr seed; "x" ^ string_of_int !seed),
+ so,
+ mk_lambdas rev_left_args (0,args,ta))
+ | 0, args, C.Sort _ ->
+ let rec mk_rels =
+ function
+ 0 -> []
+ | n -> C.Rel n :: mk_rels (n - 1) in
+ let argsno = List.length args in
+ C.Lambda
+ (C.Name "x",
+ (if argsno + List.length rev_left_args > 0 then
+ C.Appl
+ (C.MutInd (turi, typeno, []) ::
+ (List.map
+ (S.lift (argsno + 1))
+ (List.rev rev_left_args)) @
+ mk_rels argsno)
+ else
+ C.MutInd (turi,typeno,[])),
+ C.Sort C.Prop)
+ | 0, _, _ -> assert false (* seriously screwed up *)
+ | n, he::tl, C.Prod (_,_,ta) ->
+ mk_lambdas (he::rev_left_args)(n-1,tl,S.subst he ta)
+ | n,_,_ ->
+ assert false (* we should probably reduce in some context *)
+ in
+ mk_lambdas [] (paramsno, args, rty)
+ in
+ branches, outtype
+ | _ -> assert false
+ in
+ let discriminate'_tac ~term status =
+ let (proof, goal) = status in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let termty,_ =
+ CTC.type_of_aux' metasenv context term CU.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,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)::args)) ->
+ turi,typeno,exp_named_subst,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 branches,outtype =
+ mk_branches_and_outtype turi typeno consno context args
+ in
+ PET.apply_tactic
+ (T.then_
+ ~start:(EliminationTactics.elim_type_tac (C.MutInd (false_URI, 0, [])))
+ ~continuation:
+ (T.then_
+ ~start:
+ (RT.change_tac
+ ~pattern:(PET.conclusion_pattern None)
+ (fun _ m u ->
+ C.Appl [
+ C.Lambda ( C.Name "x", tty,
+ C.MutCase (turi, typeno, outtype, (C.Rel 1), branches));
+ t2 ],
+ m, u))
+ ~continuation:
+ (T.then_
+ ~start:
+ (ET.rewrite_simpl_tac
+ ~direction:`RightToLeft
+ ~pattern:(PET.conclusion_pattern None)
+ term [])
+ ~continuation:
+ (IntroductionTactics.constructor_tac ~n:1)))) status
+ | _ -> fail "not an equality"
+ in
+ PET.mk_tactic (discriminate'_tac ~term)
+
+let exn_noneq =
+ PET.Fail (lazy "Injection: not an equality")
+let exn_nothingtodo =
+ PET.Fail (lazy "Nothing to do")
+let exn_discrnonind =
+ PET.Fail (lazy "Discriminate: object is not an Inductive Definition: it's imposible")
+let exn_injwronggoal =
+ PET.Fail (lazy "Injection: goal after cut is not correct")
+let exn_noneqind =
+ PET.Fail (lazy "Injection: not an equality over elements of an inductive type")
+
+let pp ctx t =
+ let names = List.map (function Some (n,_) -> Some n | None -> None) ctx in
+ CicPp.pp t names
+
+let clear_term first_time lterm =
+ let clear_term status =
+ let (proof, goal) = status in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
+ debug_print (lazy ("\nclear di: " ^ pp context term));
+ debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
+ let g () = if first_time then raise exn_nothingtodo else T.id_tac in
+ let tactic = match term with
+ | C.Rel n ->
+ begin match List.nth context (pred n) with
+ | Some (C.Name id, _) ->
+ T.if_ ~fail:(g ()) ~start:(PST.clear ~hyps:[id]) ~continuation:T.id_tac
+ | _ -> assert false
+ end
+ | _ -> g ()
+ in
+ PET.apply_tactic tactic status
+ in
+ PET.mk_tactic clear_term
+
+let exists context = function
+ | C.Rel i -> List.nth context (pred i) <> None
+ | _ -> true
+
+let recur_on_child_tac ~before ~after =
+ let recur_on_child status =
+ let (proof, goal) = status in
+ let _, metasenv, _subst, _, _, _ = proof in
+ let _, context, _ = CicUtil.lookup_meta goal metasenv in
+ debug_print (lazy ("\nrecur_on_child"));
+ debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
+ let mk_lterm term c m ug =
+ let distance = List.length c - List.length context in
+ S.lift distance term, m, ug
+ in
+ let lterm = mk_lterm (Cic.Rel 1) in
+ let tactic = T.then_ ~start:before ~continuation:(after lterm) in
+ PET.apply_tactic tactic status
+ in
+ PET.mk_tactic recur_on_child
+
+let injection_tac ~lterm ~i ~continuation ~recur =
+ let give_name seed = function
+ | C.Name _ as name -> name
+ | C.Anonymous -> C.Name (incr seed; "y" ^ string_of_int !seed)
+ in
+ let rec mk_rels = function | 0 -> [] | n -> C.Rel n :: (mk_rels (n - 1)) in
+ let injection_tac status =
+ let (proof, goal) = status in
+ (* precondizione: t1 e t2 hanno in testa lo stesso costruttore ma
+ * differiscono (o potrebbero differire?) nell'i-esimo parametro
+ * del costruttore *)
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
+ let termty,_ =
+ CTC.type_of_aux' metasenv context term CU.empty_ugraph
+ in
+ debug_print (lazy ("\ninjection su : " ^ pp context termty));
+ match termty with (* an equality *)
+ | C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]
+ when LibraryObjects.is_eq_URI equri ->
+ let turi,typeno,ens,params =
+ match tty with (* some inductive type *)
+ | C.MutInd (turi,typeno,ens) -> turi,typeno,ens,[]
+ | C.Appl (C.MutInd (turi,typeno,ens)::params) -> turi,typeno,ens,params
+ | _ -> raise exn_noneqind
+ in
+ let t1',t2',consno = (* sono i due sottotermini che differiscono *)
+ match t1,t2 with
+ | C.Appl ((C.MutConstruct (uri1,typeno1,consno1,ens1))::applist1),
+ C.Appl ((C.MutConstruct (uri2,typeno2,consno2,ens2))::applist2)
+ when (uri1 = uri2) && (typeno1 = typeno2) &&
+ (consno1 = consno2) && (ens1 = ens2) ->
+ (* controllo ridondante *)
+ List.nth applist1 (pred i),List.nth applist2 (pred i),consno2
+ | _ -> assert false
+ in
+ let tty',_ = CTC.type_of_aux' metasenv context t1' CU.empty_ugraph in
+ let patterns,outtype =
+ match fst (CicEnvironment.get_obj CU.empty_ugraph turi) with
+ | C.InductiveDefinition (ind_type_list,_,paramsno,_)->
+ let left_params, right_params = HExtlib.split_nth paramsno params in
+ let _,_,_,constructor_list = List.nth ind_type_list typeno in
+ let i_constr_id,_ = List.nth constructor_list (consno - 1) in
+ let patterns =
+ let seed = ref 0 in
+ List.map
+ (function (id,cty) ->
+ let reduced_cty = CR.whd context cty in
+ let rec aux k = function
+ | C.Prod (_,_,tgt) when k <= paramsno ->
+ let left = List.nth left_params (k-1) in
+ aux (k+1) (S.subst left tgt)
+ | C.Prod (binder,source,target) when k > paramsno ->
+ let binder' = give_name seed binder in
+ C.Lambda (binder',source,(aux (k+1) target))
+ | _ ->
+ let nr_param_constr = k - paramsno - 1 in
+ if id = i_constr_id then C.Rel (k - i)
+ else S.lift nr_param_constr t1'
+ (* + 1 per liftare anche il lambda aggiunto
+ * esternamente al case *)
+ in S.lift 1 (aux 1 reduced_cty))
+ constructor_list
+ in
+ (* this code should be taken from cases_tac *)
+ let outtype =
+ let seed = ref 0 in
+ let rec to_lambdas te head =
+ match CR.whd context te with
+ | C.Prod (binder,so,ta) ->
+ let binder' = give_name seed binder in
+ C.Lambda (binder',so,to_lambdas ta head)
+ | _ -> head
+ in
+ let rec skip_prods params te =
+ match params, CR.whd context te with
+ | [], _ -> te
+ | left::tl, C.Prod (_,_,ta) ->
+ skip_prods tl (S.subst left ta)
+ | _, _ -> assert false
+ in
+ let abstracted_tty =
+ let tty =
+ List.fold_left (fun x y -> S.subst y x) tty left_params
+ in
+ (* non lift, ma subst coi left! *)
+ match S.lift 1 tty with
+ | C.MutInd _ as tty' -> tty'
+ | C.Appl l ->
+ let keep,abstract = HExtlib.split_nth (paramsno +1) l in
+ let keep = List.map (S.lift paramsno) keep in
+ C.Appl (keep@mk_rels (List.length abstract))
+ | _ -> assert false
+ in
+ match ind_type_list with
+ | [] -> assert false
+ | (_,_,ty,_)::_ ->
+ (* this is in general wrong, do as in cases_tac *)
+ to_lambdas (skip_prods left_params ty)
+ (C.Lambda
+ (C.Name "cased", abstracted_tty,
+ (* here we should capture right parameters *)
+ (* 1 for his Lambda, one for the Lambda outside the match
+ * and then one for each to_lambda *)
+ S.lift (2+List.length right_params) tty'))
+ in
+ patterns,outtype
+ | _ -> raise exn_discrnonind
+ in
+ let cutted = C.Appl [C.MutInd (equri,0,[]) ; tty' ; t1' ; t2'] in
+ let changed =
+ C.Appl [ C.Lambda (C.Name "x", tty,
+ C.MutCase (turi,typeno,outtype,C.Rel 1,patterns)) ; t1]
+ in
+ (* check if cutted and changed are well typed and if t1' ~ changed *)
+ let go_on =
+ try
+ let _,g = CTC.type_of_aux' metasenv context cutted
+ CU.empty_ugraph
+ in
+ let _,g = CTC.type_of_aux' metasenv context changed g in
+ fst (CR.are_convertible ~metasenv context t1' changed g)
+ with
+ | CTC.TypeCheckerFailure _ -> false
+ in
+ if not go_on then begin
+ HLog.warn "destruct: injection failed";
+ PET.apply_tactic continuation status
+ end else
+ let fill_cut_tac term =
+ let fill_cut status =
+ debug_print (lazy "riempio il cut");
+ let (proof, goal) = status in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,gty = CicUtil.lookup_meta goal metasenv in
+ let gty = Unshare.unshare gty in
+ let new_t1' = match gty with
+ | (C.Appl (C.MutInd (_,_,_)::_::t::_)) -> t
+ | _ -> raise exn_injwronggoal
+ in
+ debug_print (lazy ("metto: " ^ pp context changed));
+ debug_print (lazy ("al posto di: " ^ pp context new_t1'));
+ debug_print (lazy ("nel goal: " ^ pp context gty));
+ debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
+ debug_print (lazy ("e poi rewrite con: "^pp context term));
+ let tac = T.seq ~tactics:[
+ RT.change_tac
+ ~pattern:(None, [], Some (PEH.pattern_of ~term:gty [new_t1']))
+ (fun _ m u -> changed,m,u);
+ ET.rewrite_simpl_tac
+ ~direction:`LeftToRight
+ ~pattern:(PET.conclusion_pattern None)
+ term [];
+ ET.reflexivity_tac
+ ] in
+ PET.apply_tactic tac status
+ in
+ PET.mk_tactic fill_cut
+ in
+ debug_print (lazy ("CUT: " ^ pp context cutted));
+ let tactic =
+ T.thens ~start: (P.cut_tac cutted)
+ ~continuations:[
+ recur_on_child_tac continuation recur;
+ fill_cut_tac term
+ ]
+ in
+ PET.apply_tactic tactic status
+ | _ -> raise exn_noneq
+ in
+ PET.mk_tactic injection_tac
+
+let subst_tac ~lterm ~direction ~where ~continuation ~recur =
+ let subst_tac status =
+ let (proof, goal) = status in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
+ debug_print (lazy ("\nsubst " ^ (match direction with `LeftToRight -> "->" | `RightToLeft -> "<-") ^ " di: " ^ pp context term));
+ let tactic = match where with
+ | None ->
+ debug_print (lazy ("nella conclusione"));
+ let pattern = PET.conclusion_pattern None in
+ let tactic = ET.rewrite_tac ~direction ~pattern term [] in
+ T.then_ ~start:(T.try_tactic ~tactic) ~continuation
+ | Some name ->
+ debug_print (lazy ("nella premessa: " ^ name));
+ let pattern = None, [name, PET.hole], None in
+ let start = ET.rewrite_tac ~direction ~pattern term [] in
+ let ok_tactic = recur_on_child_tac continuation recur in
+ T.if_ ~start ~continuation:ok_tactic ~fail:continuation
+ in
+ PET.apply_tactic tactic status
+ in
+ PET.mk_tactic subst_tac
+
+let rec destruct ~first_time lterm =
+ let are_convertible hd1 hd2 metasenv context =
+ fst (CR.are_convertible ~metasenv context hd1 hd2 CU.empty_ugraph)
+ in
+ let recur = destruct ~first_time:false in
+ let destruct status =
+ let (proof, goal) = status in
+ let _,metasenv,_subst, _,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
+ let tactic = if not (first_time || exists context term) then T.id_tac else begin
+ debug_print (lazy ("\ndestruct di: " ^ pp context term));
+ debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
+ let termty,_ = CTC.type_of_aux' metasenv context term CU.empty_ugraph in
+ debug_print (lazy ("\ndestruct su: " ^ pp context termty));
+ let mk_lterm term c m ug =
+ let distance = List.length c - List.length context in
+ S.lift distance term, m, ug
+ in
+ let lterm = mk_lterm term in
+ let mk_subst_chain direction index with_what what =
+ let k = match term with C.Rel i -> i | _ -> -1 in
+ let rec traverse_context first_time j = function
+ | [] ->
+ let continuation =
+ T.seq ~tactics:[
+ clear_term first_time lterm;
+ clear_term false (mk_lterm what);
+ clear_term false (mk_lterm with_what)
+ ]
+ in
+ subst_tac ~direction ~lterm ~where:None ~continuation ~recur
+ | Some (C.Name name, _) :: tl when j < index && j <> k ->
+ debug_print (lazy ("\nsubst programmata: cosa: " ^ string_of_int index ^ ", dove: " ^ string_of_int j));
+ subst_tac ~direction ~lterm ~where:(Some name) ~recur
+ ~continuation:(traverse_context false (succ j) tl)
+ | _ :: tl -> traverse_context first_time (succ j) tl
+ in
+ traverse_context first_time 1 context
+ in
+ match termty with
+ | C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]
+ when LibraryObjects.is_eq_URI equri ->
+ begin match t1,t2 with
+(* injection part *)
+ | C.MutConstruct _,
+ C.MutConstruct _
+ when t1 = t2 -> clear_term first_time lterm
+ | C.Appl (C.MutConstruct _ as mc1 :: applist1),
+ C.Appl (C.MutConstruct _ as mc2 :: applist2)
+ when mc1 = mc2 ->
+ let rec traverse_list first_time i l1 l2 =
+ match l1, l2 with
+ | [], [] -> clear_term first_time lterm
+ | hd1 :: tl1, hd2 :: tl2 ->
+ if are_convertible hd1 hd2 metasenv context then
+ traverse_list first_time (succ i) tl1 tl2
+ else
+ injection_tac ~i ~lterm ~recur ~continuation:
+ (traverse_list false (succ i) tl1 tl2)
+ | _ -> assert false
+ (* i 2 termini hanno in testa lo stesso costruttore,
+ * ma applicato a un numero diverso di termini *)
+ in
+ traverse_list first_time 1 applist1 applist2
+(* discriminate part *)
+ | C.MutConstruct (_,_,consno1,ens1),
+ C.MutConstruct (_,_,consno2,ens2)
+ | C.MutConstruct (_,_,consno1,ens1),
+ C.Appl ((C.MutConstruct (_,_,consno2,ens2))::_)
+ | C.Appl ((C.MutConstruct (_,_,consno1,ens1))::_),
+ C.MutConstruct (_,_,consno2,ens2)
+ | C.Appl ((C.MutConstruct (_,_,consno1,ens1))::_),
+ C.Appl ((C.MutConstruct (_,_,consno2,ens2))::_)
+ when (consno1 <> consno2) || (ens1 <> ens2) ->
+ discriminate_tac ~term
+(* subst part *)
+ | C.Rel _, C.Rel _ when t1 = t2 ->
+ T.seq ~tactics:[
+ clear_term first_time lterm;
+ clear_term false (mk_lterm t1)
+ ]
+ | C.Rel i1, C.Rel i2 when i1 < i2 ->
+ mk_subst_chain `LeftToRight i1 t2 t1
+ | C.Rel i1, C.Rel i2 when i1 > i2 ->
+ mk_subst_chain `RightToLeft i2 t1 t2
+ | C.Rel i1, _ when DTI.does_not_occur i1 t2 ->
+ mk_subst_chain `LeftToRight i1 t2 t1
+ | _, C.Rel i2 when DTI.does_not_occur i2 t1 ->
+ mk_subst_chain `RightToLeft i2 t1 t2
+(* else part *)
+ | _ when first_time -> raise exn_nothingtodo
+ | _ (* when not first time *) -> T.id_tac
+ end
+ | _ when first_time -> raise exn_nothingtodo
+ | _ (* when not first time *) -> T.id_tac
+ end in
+ PET.apply_tactic tactic status
+ in
+ PET.mk_tactic destruct
+
+(* destruct performs either injection or discriminate or subst *)
+let destruct_tac xterms =
+ let destruct status =
+ let (proof, goal) = status in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,_ = CicUtil.lookup_meta goal metasenv in
+ let mk_lterm term c m ug =
+ let distance = List.length c - List.length context in
+ S.lift distance term, m, ug
+ in
+ let tactics = match xterms with
+ | Some terms ->
+ let map term = destruct ~first_time:false (mk_lterm term) in
+ List.map map terms
+ | None ->
+ let rec mk_tactics first_time i tacs = function
+ | [] -> List.rev tacs
+ | Some _ :: tl ->
+ let lterm = mk_lterm (C.Rel i) in
+ let tacs = destruct ~first_time lterm :: tacs in
+ mk_tactics false (succ i) tacs tl
+ | _ :: tl -> mk_tactics first_time (succ i) tacs tl
+ in
+ mk_tactics false 1 [] context
+ in
+ PET.apply_tactic (T.seq ~tactics) status
+ in
+ PET.mk_tactic destruct
projects / helm.git / blobdiff