X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fcomponents%2Fng_refiner%2FnCicRefiner.ml;h=550c75e9382c4ec9173f76d1da3d9428f28644d0;hb=446bec03de2d1e48ee612cd8020777aeeb7fbf06;hp=ea502b68592070aad0062c6002c5143059cfd0dc;hpb=83a494ff9e15871231c8338df95f89926f2293ba;p=helm.git

diff --git a/matita/components/ng_refiner/nCicRefiner.ml b/matita/components/ng_refiner/nCicRefiner.ml
index ea502b685..550c75e93 100644
--- a/matita/components/ng_refiner/nCicRefiner.ml
+++ b/matita/components/ng_refiner/nCicRefiner.ml
@@ -505,13 +505,14 @@ and try_coercions status
   (* we try with a coercion *)
   let rec first exc = function
   | [] ->   
-     let expty =
-      match expty with
-         `Type expty -> status#ppterm ~metasenv ~subst ~context expty
-       | `Sort -> "[[sort]]"
-       | `Prod -> "[[prod]]" in
       pp (lazy "WWW: no more coercions!");      
-      raise (wrap_exc (lazy (localise orig_t, Printf.sprintf
+      raise (wrap_exc (lazy
+       let expty =
+        match expty with
+           `Type expty -> status#ppterm ~metasenv ~subst ~context expty
+         | `Sort -> "[[sort]]"
+         | `Prod -> "[[prod]]" in
+         (localise orig_t, Printf.sprintf
         "The term\n%s\nhas type\n%s\nbut is here used with type\n%s"
         (status#ppterm ~metasenv ~subst ~context t)
         (status#ppterm ~metasenv ~subst ~context infty)
@@ -909,12 +910,19 @@ and force_to_sort status metasenv subst context t orig_t localise ty =
       metasenv, subst, t, ty
   with
       Failure _ -> 
+        let msg =
+         (lazy (localise orig_t, 
+           "The type of " ^ status#ppterm ~metasenv ~subst ~context t ^
+           " is not a sort: " ^ status#ppterm ~metasenv ~subst ~context ty)) in
         let ty = NCicReduction.whd status ~subst context ty in
+        let exn =
+         if NCicUnification.could_reduce status ~subst context ty then
+          Uncertain msg
+         else
+          RefineFailure msg
+        in
           try_coercions status ~localise metasenv subst context
-            t orig_t ty `Sort 
-             (Uncertain (lazy (localise orig_t, 
-             "The type of " ^ status#ppterm ~metasenv ~subst ~context t ^
-             " is not a sort: " ^ status#ppterm ~metasenv ~subst ~context ty)))
+            t orig_t ty `Sort exn
 
 and sort_of_prod status localise metasenv subst context orig_s orig_t (name,s)
  t (t1, t2)