X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fcomponents%2Ftactics%2FprimitiveTactics.ml;fp=matita%2Fcomponents%2Ftactics%2FprimitiveTactics.ml;h=0000000000000000000000000000000000000000;hb=0fde70bd19b8fdfa72b807b9713a02ad1bd91b5b;hp=2862d3c5d44263b414866938c5aca99fb76aef6a;hpb=f61ffe97078aab1e47ee1b7f212e707b0412e77e;p=helm.git

diff --git a/matita/components/tactics/primitiveTactics.ml b/matita/components/tactics/primitiveTactics.ml
deleted file mode 100644
index 2862d3c5d..000000000
--- a/matita/components/tactics/primitiveTactics.ml
+++ /dev/null
@@ -1,1072 +0,0 @@
-(* 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.oblivion_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.oblivion_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.oblivion_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.oblivion_ugraph
-  in
-  let t = 
-    if List.length arguments = 0 then term' else Cic.Appl (term'::arguments)
-  in
-  subst,newmetasenv',t
-
-let rec count_prods subst context ty =
- match CicReduction.whd ~subst context ty with
-    Cic.Prod (n,s,t) -> 1 + count_prods subst (Some (n,Cic.Decl s)::context) t
-  | _ -> 0
-
-let apply_with_subst ~term ~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' ~subst context term' CicUniv.oblivion_ugraph
-   in
-   let termty =
-     CicSubstitution.subst_vars exp_named_subst_diff termty in
-   let goal_arity = count_prods subst 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
-   let newproof = 
-     let u,m,_,p,t,l = newproof in
-     u,m,subst,p,t,l
-   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
-    let status = 
-      if subst <> [] then
-        let (u,m,_,p,t,l), g = status in (u,m,subst,p,t,l), g
-      else status
-    in
-     apply_with_subst ~term ~maxmeta status
-  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 applyP_tac ~term =
-   let applyP_tac status =
-      let res = PET.apply_tactic (apply_tac ~term) status in res
-   in
-   PET.mk_tactic applyP_tac
-
-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.oblivion_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)
-
-(* FG: exact_tac := apply_tac as in NTactics *)
-let exact_tac ~term = apply_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 ~subst ~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 subst context' pred arg' cpattern' = function
-      | []           -> metasenv, subst, pred, arg'
-      | arg :: tail -> 
-(* FG: we find the predicate for the eliminator as in the rewrite tactic ****)
-	 let argty, _ = TC.type_of_aux' metasenv ~subst context arg ugraph in
-         let argty = CicReduction.whd ~subst 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 ~subst ~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 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, C.Implicit None, pred) in
-	 let cpattern' = C.Lambda (C.Anonymous, C.Implicit None, cpattern') in
-         mk_pred metasenv subst (hyp :: context') pred arg' cpattern' tail 
-   in
-   let metasenv, subst, pred, arg = 
-      mk_pred metasenv subst context goal arg cpattern (List.rev actual_args)
-   in
-   HLog.debug ("PREDICATE CONTEXT:\n" ^ CicPp.ppcontext ~metasenv context);
-   HLog.debug ("PREDICATE: " ^ CicPp.ppterm ~metasenv pred ^ " ARGS: " ^ String.concat " " (List.map (CicPp.ppterm ~metasenv) actual_args));
-   metasenv, subst, 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
-
-(* ANCORA DA DEBUGGARE *)
-
-exception UnableToDetectTheTermThatMustBeGeneralizedYouMustGiveItExplicitly;;
-exception TheSelectedTermsMustLiveInTheGoalContext
-exception AllSelectedTermsMustBeConvertible;;
-exception GeneralizationInHypothesesNotImplementedYet;;
-
-let generalize_tac 
- ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
- pattern
- =
-  let module PET = ProofEngineTypes in
-  let generalize_tac mk_fresh_name_callback
-       ~pattern:(term,hyps_pat,_) status
-  =
-   if hyps_pat <> [] then raise GeneralizationInHypothesesNotImplementedYet;
-   let (proof, goal) = status in
-   let module C = Cic in
-   let module T = Tacticals in
-    let uri,metasenv,subst,pbo,pty, attrs = proof in
-    let (_,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
-    let subst,metasenv,u,selected_hyps,terms_with_context =
-     ProofEngineHelpers.select ~metasenv ~subst ~ugraph:CicUniv.oblivion_ugraph
-      ~conjecture ~pattern in
-    let context = CicMetaSubst.apply_subst_context subst context in
-    let metasenv = CicMetaSubst.apply_subst_metasenv subst metasenv in
-    let pbo = lazy (CicMetaSubst.apply_subst subst (Lazy.force pbo)) in
-    let pty = CicMetaSubst.apply_subst subst pty in
-    let term =
-     match term with
-        None -> None
-      | Some term ->
-          Some (fun context metasenv ugraph -> 
-                  let term, metasenv, ugraph = term context metasenv ugraph in
-                   CicMetaSubst.apply_subst subst term,
-                    CicMetaSubst.apply_subst_metasenv subst metasenv,
-                    ugraph)
-    in
-    let u,typ,term, metasenv' =
-     let context_of_t, (t, metasenv, u) =
-      match terms_with_context, term with
-         [], None ->
-          raise
-           UnableToDetectTheTermThatMustBeGeneralizedYouMustGiveItExplicitly
-       | [], Some t -> context, t context metasenv u
-       | (context_of_t, _)::_, Some t -> 
-           context_of_t, t context_of_t metasenv u
-       | (context_of_t, t)::_, None -> context_of_t, (t, metasenv, u)
-     in
-      let t,e_subst,metasenv' =
-       try
-        CicMetaSubst.delift_rels [] metasenv
-         (List.length context_of_t - List.length context) t
-       with
-        CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
-         raise TheSelectedTermsMustLiveInTheGoalContext
-      in
-       (*CSC: I am not sure about the following two assertions;
-         maybe I need to propagate the new subst and metasenv *)
-       assert (e_subst = []);
-       assert (metasenv' = metasenv);
-       let typ,u = CicTypeChecker.type_of_aux' ~subst metasenv context t u in
-        u,typ,t,metasenv
-    in
-    (* We need to check:
-        1. whether they live in the context of the goal;
-           if they do they are also well-typed since they are closed subterms
-           of a well-typed term in the well-typed context of the well-typed
-           term
-        2. whether they are convertible
-    *)
-    ignore (
-     List.fold_left
-      (fun u (context_of_t,t) ->
-        (* 1 *)
-        let t,subst,metasenv'' =
-         try
-          CicMetaSubst.delift_rels [] metasenv'
-           (List.length context_of_t - List.length context) t
-         with
-          CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
-           raise TheSelectedTermsMustLiveInTheGoalContext in
-        (*CSC: I am not sure about the following two assertions;
-          maybe I need to propagate the new subst and metasenv *)
-        assert (subst = []);
-        assert (metasenv'' = metasenv');
-        (* 2 *)
-        let b,u1 = CicReduction.are_convertible ~subst context term t u in 
-         if not b then 
-          raise AllSelectedTermsMustBeConvertible
-         else
-          u1
-      ) u terms_with_context) ;
-    let status = (uri,metasenv',subst,pbo,pty, attrs),goal in
-    let proof,goals =
-     PET.apply_tactic 
-      (T.thens 
-        ~start:
-          (cut_tac 
-           (C.Prod(
-             (mk_fresh_name_callback metasenv context C.Anonymous ~typ:typ), 
-             typ,
-             (ProofEngineReduction.replace_lifting_csc 1
-               ~equality:(==) 
-               ~what:(List.map snd terms_with_context)
-               ~with_what:(List.map (function _ -> C.Rel 1) terms_with_context)
-               ~where:ty)
-           )))
-        ~continuations:
-          [(apply_tac ~term:(C.Appl [C.Rel 1; CicSubstitution.lift 1 term])) ;
-            T.id_tac])
-        status
-    in
-     let _,metasenv'',_,_,_, _ = proof in
-      (* CSC: the following is just a bad approximation since a meta
-         can be closed and then re-opened! *)
-      (proof,
-        goals @
-         (List.filter
-           (fun j -> List.exists (fun (i,_,_) -> i = j) metasenv'')
-           (ProofEngineHelpers.compare_metasenvs ~oldmetasenv:metasenv
-             ~newmetasenv:metasenv')))
- in
-  PET.mk_tactic (generalize_tac mk_fresh_name_callback ~pattern)
-;;
-
-let generalize_pattern_tac pattern =
- let generalize_pattern_tac (proof,goal) =
-   let _,metasenv,_,_,_,_ = proof in
-   let conjecture = CicUtil.lookup_meta goal metasenv in
-   let _,context,_ = conjecture in 
-   let generalize_hyps =
-    let _,hpatterns,_ = ProofEngineHelpers.sort_pattern_hyps context pattern in
-     List.map fst hpatterns in
-   let ids_and_patterns =
-    List.map
-     (fun id ->
-       let rel,_ = ProofEngineHelpers.find_hyp id context in
-        id,(Some (fun ctx m u -> CicSubstitution.lift (List.length ctx - List.length context) rel,m,u), [], Some (ProofEngineTypes.hole))
-     ) generalize_hyps in
-   let tactics =
-    List.map
-     (function (id,pattern) ->
-       Tacticals.then_ ~start:(generalize_tac pattern)
-        ~continuation:(Tacticals.try_tactic
-          (ProofEngineStructuralRules.clear [id]))
-     ) ids_and_patterns
-   in
-    PET.apply_tactic (Tacticals.seq tactics) (proof,goal)
- in
-  PET.mk_tactic (generalize_pattern_tac)
-;;
-
-let pattern_after_generalize_pattern_tac (tp, hpatterns, cpattern) =
- let cpattern =
-  match cpattern with
-     None -> ProofEngineTypes.hole
-   | Some t -> t
- in
- let cpattern =
-  List.fold_left
-   (fun t (_,ty) -> Cic.Prod (Cic.Anonymous, ty, t)) cpattern hpatterns
- in
-  tp, [], Some cpattern
-;;
-
-let elim_tac ?using ?(pattern = PET.conclusion_pattern None) term = 
- let elim_tac pattern (proof, goal) =
-   let ugraph = CicUniv.oblivion_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 pattern = pattern_after_generalize_pattern_tac pattern in
-   let cpattern =
-    match pattern with 
-      | None, [], Some cpattern -> cpattern
-      | _ -> raise (PET.Fail (lazy "not implemented")) in    
-    let termty,_ugraph = TC.type_of_aux' metasenv ~subst context term ugraph in
-    let termty = CicReduction.whd ~subst 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' ~subst context ty ugraph in
-      let ext =
-       match ty_ty with
-          C.Sort C.Prop -> "_ind"
-        | C.Sort C.Set  -> "_rec"
-        | C.Sort (C.CProp _) -> "_rect"
-        | 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' ~subst 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', subst, pred, term, actual_args = match pattern with 
-      | None, [], Some (C.Implicit (Some `Hole)) ->
-         metasenv', subst, C.Implicit None, term, []
-      | _                                        ->
-         mk_predicate_for_elim 
-	    ~args_no ~context ~ugraph ~cpattern
-	    ~metasenv:metasenv' ~subst ~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'',subst,_ugraph = 
-         CicRefine.type_of metasenv' subst context term_to_refine ugraph
-      in
-      let ipred = match refined_term with
-         | C.Appl ts -> List.nth ts (List.length ts - pred_pos)
-	 | _         -> assert false
-      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''',_,_,_, _) = 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
-(* FG: we use ipred (instantiated pred) instead of pred (not instantiated) *)
-      let continuation = beta_after_elim_tac upto ipred in
-      let dummy_status = proof,goal in
-      PET.apply_tactic
-         (T.then_ ~start:(PET.mk_tactic (fun _ -> res)) ~continuation)
-         dummy_status
-   in
-   let reorder_pattern ((proof, goal) as status) =
-     let _,metasenv,_,_,_,_ = proof in
-     let conjecture = CicUtil.lookup_meta goal metasenv in
-     let _,context,_ = conjecture in
-     let pattern = ProofEngineHelpers.sort_pattern_hyps context pattern in
-      PET.apply_tactic
-       (Tacticals.then_ ~start:(generalize_pattern_tac pattern)
-         ~continuation:(PET.mk_tactic (elim_tac pattern))) status
-   in
-    PET.mk_tactic reorder_pattern
-;;
-
-let cases_intros_tac ?(howmany=(-1)) ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[]) ?(pattern = PET.conclusion_pattern None) term =
- let cases_tac pattern (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 pattern = pattern_after_generalize_pattern_tac pattern in
-  let _cpattern =
-   match pattern with 
-     | None, [], Some cpattern ->
-        let rec is_hole =
-         function
-            Cic.Implicit (Some `Hole) -> true
-          | Cic.Prod (Cic.Anonymous,so,tgt) -> is_hole so && is_hole tgt
-          | _ -> false
-        in
-         if not (is_hole cpattern) then
-          raise (PET.Fail (lazy "not implemented"))
-     | _ -> raise (PET.Fail (lazy "not implemented")) in    
-  let termty,_ = TC.type_of_aux' metasenv context term CicUniv.oblivion_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.oblivion_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 outtypes =
-    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 false) ~where:captured;
-         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 captured_ty = function
-      | 0 -> captured_ty
-      | 1 -> 
-          C.Lambda (C.Name "matched", captured_term_ty, (add_lambdas captured_ty 0))
-      | n -> 
-           C.Lambda (C.Name ("right_"^(string_of_int (n-1))),
-                     C.Implicit None, (add_lambdas captured_ty (n-1)))
-    in
-    List.map (fun x -> add_lambdas x n_lambdas) captured_ty
-  in
-  let rec first = (* easier than using tacticals *)
-  function 
-  | [] -> raise (PET.Fail (lazy ("unable to generate a working outtype")))
-  | outtype::rest -> 
-     let term_to_refine = C.MutCase (uri,typeno,outtype,term,patterns) in
-     try
-       let refined_term,_,metasenv'',_ = 
-         CicRefine.type_of_aux' metasenv' context term_to_refine
-           CicUniv.oblivion_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
-     with PET.Fail _ | CicRefine.RefineFailure _ | CicRefine.Uncertain _ -> first rest
-  in
-   first outtypes
- in
-   let reorder_pattern ((proof, goal) as status) =
-     let _,metasenv,_,_,_,_ = proof in
-     let conjecture = CicUtil.lookup_meta goal metasenv in
-     let _,context,_ = conjecture in
-     let pattern = ProofEngineHelpers.sort_pattern_hyps context pattern in
-      PET.apply_tactic
-       (Tacticals.then_ ~start:(generalize_pattern_tac pattern)
-         ~continuation:(PET.mk_tactic (cases_tac pattern))) status
-   in
-    PET.mk_tactic reorder_pattern
-;;
-
-
-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)])
-;;