X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_kernel%2FnCicUntrusted.ml;h=022482b0a9e60c44e20398d586b74bd9ddaa9e2a;hb=c450fdfb1b02eb69e5e7ef25f0acdf80157710df;hp=524a00cd35f73cdd4477b8e3191f30ceff7bca31;hpb=7a651a85d575ff0294f76f78d7771b96e50c5012;p=helm.git

diff --git a/helm/software/components/ng_kernel/nCicUntrusted.ml b/helm/software/components/ng_kernel/nCicUntrusted.ml
index 524a00cd3..022482b0a 100644
--- a/helm/software/components/ng_kernel/nCicUntrusted.ml
+++ b/helm/software/components/ng_kernel/nCicUntrusted.ml
@@ -271,9 +271,9 @@ let rec replace_in_subst i f = function
   | (j,e)::tl when j=i -> (i,f e) :: tl
   | x::tl -> x :: replace_in_subst i f tl
 ;;
-          
+
 let set_kind newkind attrs = 
-  newkind :: List.filter (fun x -> not (is_kind x)) attrs 
+  (newkind :> NCic.meta_attr) :: List.filter (fun x -> not (is_kind x)) attrs 
 ;;
 
 let max_kind k1 k2 = 
@@ -312,3 +312,39 @@ let relations_of_menv subst m c =
 let sort_metasenv subst (m : NCic.metasenv) =
   (MS.topological_sort m (relations_of_menv subst m) : NCic.metasenv)
 ;;
+
+let count_occurrences ~subst n t = 
+  let occurrences = ref 0 in
+  let rec aux k _ = function
+    | C.Rel m when m = n+k -> incr occurrences
+    | C.Rel _m -> ()
+    | C.Implicit _ -> ()
+    | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) -> (* closed meta *) ()
+    | C.Meta (mno,(s,l)) ->
+         (try
+            (* possible optimization here: try does_not_occur on l and
+               perform substitution only if DoesOccur is raised *)
+            let _,_,term,_ = NCicUtils.lookup_subst mno subst in
+            aux (k-s) () (NCicSubstitution.subst_meta (0,l) term)
+          with NCicUtils.Subst_not_found _ -> () (*match l with
+          | C.Irl len -> if not (n+k >= s+len || s > nn+k) then raise DoesOccur
+          | C.Ctx lc -> List.iter (aux (k-s) ()) lc*))
+    | t -> NCicUtils.fold (fun _ k -> k + 1) k aux () t
+  in
+   aux 0 () t;
+   !occurrences
+;;
+
+exception Found_variable
+
+let looks_closed t = 
+  let rec aux k _ = function
+    | C.Rel m when k < m -> raise Found_variable
+    | C.Rel _m -> ()
+    | C.Implicit _ -> ()
+    | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) -> (* closed meta *) ()
+    | C.Meta _ -> raise Found_variable
+    | t -> NCicUtils.fold (fun _ k -> k + 1) k aux () t
+  in
+  try aux 0 () t; true with Found_variable -> false
+;;