- decompose tactic: decomposable constants are now allowed (they are unfolded)

[helm.git] / helm / software / components / tactics / eliminationTactics.ml

diff --git a/helm/software/components/tactics/eliminationTactics.ml b/helm/software/components/tactics/eliminationTactics.ml
index 37a4f713688a21ac4bcbf65082466b190d10c2a9..f1a9988eb96ea1adbdf447006f794039b10b2265 100644 (file)
--- a/helm/software/components/tactics/eliminationTactics.ml
+++ b/helm/software/components/tactics/eliminationTactics.ml
@@ -32,9 +32,29 @@ module S = ProofEngineStructuralRules
 module F = FreshNamesGenerator
 module E = ProofEngineTypes
 module H = ProofEngineHelpers
+module R = ReductionTactics
+
+(*
+(* search in term the Inductive Types and return a list of uris as triples like this: (uri,typeno,exp_named_subst) *)
+let search_inductive_types ty =
+   let rec aux types = function 
+      | C.MutInd (uri, typeno, _) when (not (List.mem (uri, typeno) types)) -> 
+         (uri, typeno) :: types
+      | C.Appl applist -> List.fold_left aux types applist
+      | _              -> types
+   in
+   aux [] ty
+(* N.B: in un caso tipo (and A forall C:Prop.(or B C)) l'or *non* viene selezionato! *)
+*)
 
 (* unexported tactics *******************************************************)
 
+type type_class = Other
+                | Ind
+               | Con of C.lazy_term
+
+let premise_pattern what = None, [what, C.Implicit (Some `Hole)], None 
+
 let rec scan_tac ~old_context_length ~index ~tactic =
    let scan_tac status =
       let (proof, goal) = status in
@@ -51,29 +71,37 @@ let rec scan_tac ~old_context_length ~index ~tactic =
                in
               try E.apply_tactic tac status 
               with E.Fail _ -> aux (pred index)
-      in aux (index + context_length - old_context_length - 1)
+      in aux (index + context_length - old_context_length)
    in
    E.mk_tactic scan_tac
 
-let rec check_inductive_types types = function 
-   | C.MutInd (uri, typeno, _) -> List.mem (uri, typeno) types
-   | C.Appl (hd :: tl)         -> check_inductive_types types hd
-   | _                         -> false
+let rec check_types types = function 
+   | C.MutInd (uri, typeno, _) -> 
+      if List.mem (uri, Some typeno) types then Ind else Other
+   | C.Const (uri, _) as t     -> 
+      if List.mem (uri, None) types then Con (E.const_lazy_term t) else Other
+   | C.Appl (hd :: tl)         -> check_types types hd
+   | _                         -> Other
 
-let elim_clear_tac ~mk_fresh_name_callback ~types ~what =
-   let elim_clear_tac status =
+let elim_clear_unfold_tac ~mk_fresh_name_callback ~types ~what =
+   let elim_clear_unfold_tac status =
       let (proof, goal) = status in
       let _, metasenv, _, _ = proof in
       let _, context, _ = CicUtil.lookup_meta goal metasenv in
       let index, ty = H.lookup_type metasenv context what in
-      if check_inductive_types types ty then 
-         let tac = T.then_ ~start:(P.elim_intros_tac ~mk_fresh_name_callback (C.Rel index))
-                          ~continuation:(S.clear [what])
-        in
-        E.apply_tactic tac status
-      else raise (E.Fail (lazy "unexported elim_clear: not an eliminable type"))
+      match check_types types ty with 
+         | Ind   ->
+           let tac = T.then_ ~start:(P.elim_intros_tac ~mk_fresh_name_callback (C.Rel index))
+                             ~continuation:(S.clear [what])
+           in
+           E.apply_tactic tac status
+         | Con t ->
+           let tac = R.unfold_tac (Some t) ~pattern:(premise_pattern what) in
+           E.apply_tactic tac status
+        | Other -> 
+           raise (E.Fail (lazy "unexported elim_clear: not an eliminable type"))
    in
-   E.mk_tactic elim_clear_tac
+   E.mk_tactic elim_clear_unfold_tac
 
 (* elim type ****************************************************************)
 
@@ -102,17 +130,6 @@ let debug_print = fun _ -> ()
   (** debugging print *)
 let warn s = debug_print (lazy ("DECOMPOSE: " ^ (Lazy.force s)))
 
-(* search in term the Inductive Types and return a list of uris as triples like this: (uri,typeno,exp_named_subst) *)
-let search_inductive_types ty =
-   let rec aux types = function 
-      | C.MutInd (uri, typeno, _) when (not (List.mem (uri, typeno) types)) -> 
-         (uri, typeno) :: types
-      | C.Appl applist -> List.fold_left aux types applist
-      | _              -> types
-   in
-   aux [] ty
-(* N.B: in un caso tipo (and A forall C:Prop.(or B C)) l'or *non* viene selezionato! *)
-
 (* roba seria ------------------------------------------------------------- *)
 
 let decompose_tac ?(mk_fresh_name_callback = F.mk_fresh_name ~subst:[])
@@ -122,7 +139,7 @@ let decompose_tac ?(mk_fresh_name_callback = F.mk_fresh_name ~subst:[])
       let _, metasenv,_,_ = proof in
       let _, context, _ = CicUtil.lookup_meta goal metasenv in
       let types = List.rev_append user_types (FwdQueries.decomposables dbd) in
-      let tactic = elim_clear_tac ~mk_fresh_name_callback ~types in
+      let tactic = elim_clear_unfold_tac ~mk_fresh_name_callback ~types in
       let old_context_length = List.length context in      
       let tac = match what with
         | Some what ->