X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Facic_procedural%2FproceduralOptimizer.ml;h=c5a27efc44942bbd8e7b028a99791779e9be9a47;hb=72cd94b68037956a70b98cfa54f316fd54e52bae;hp=0364803c73d82c8552aa4e01b9e3b7d6b1c1f165;hpb=1e1f24496beba354fb3f550496858b5755d9be0b;p=helm.git

diff --git a/helm/software/components/acic_procedural/proceduralOptimizer.ml b/helm/software/components/acic_procedural/proceduralOptimizer.ml
index 0364803c7..c5a27efc4 100644
--- a/helm/software/components/acic_procedural/proceduralOptimizer.ml
+++ b/helm/software/components/acic_procedural/proceduralOptimizer.ml
@@ -99,7 +99,9 @@ let rec opt_letin g st es c name v w t =
          | v when H.is_proof c v && H.is_atomic v          ->
 	    let x = S.subst v t in
 	    opt_proof g (info st "Optimizer: remove 5") true c x 
-	 | v                                               ->
+(*	 | v when t = C.Rel 1                              ->
+	    g (info st "Optimizer: remove 6") v 
+*)	 | v                                               ->
 	    g st (C.LetIn (name, v, w, t))
       in
       if es then opt_term g st es c v else g st v
@@ -190,6 +192,10 @@ and opt_mutcase_critical g st es c uri tyno outty arg cases =
       opt_mutcase_plain g st es c uri tyno outty arg cases
    else
    let predicate = clear_absts rpsno (1 - sort_disp) outty in   
+   if H.occurs c ~what:(C.Rel 0) ~where:predicate then
+(* FG: the transformation is not possible, we fall back into the plain case *)
+      opt_mutcase_plain g st es c uri tyno outty arg cases
+   else
    let is_recursive t =
       I.S.mem tyno (I.get_mutinds_of_uri uri t) 
    in
@@ -209,8 +215,13 @@ and opt_mutcase_critical g st es c uri tyno outty arg cases =
    in
    let lifted_cases = List.map2 map2 cases constructors in
    let args = eliminator :: lps @ predicate :: lifted_cases @ rps @ [arg] in
-   let x = H.refine c (C.Appl args) in
-   opt_proof g (info st "Optimizer: remove 3") es c x
+   try 
+      let x = H.refine c (C.Appl args) in
+      opt_proof g (info st "Optimizer: remove 3") es c x	 
+   with e ->
+(* FG: the transformation is not possible, we fall back into the plain case *)
+      let st = info st ("Optimizer: refine_error: " ^ Printexc.to_string e) in
+      opt_mutcase_plain g st es c uri tyno outty arg cases
 
 and opt_mutcase_plain g st es c uri tyno outty arg cases =
    let g st v =