fixed a list.nth called on a too short list

diff --git a/helm/software/components/tactics/proofEngineReduction.ml b/helm/software/components/tactics/proofEngineReduction.ml
index ec69074369663cabc55ba782f17cde1a9ef78d76..016a7ba994fbe54593e68ac96647981ce0505b4e 100644 (file)
--- a/helm/software/components/tactics/proofEngineReduction.ml
+++ b/helm/software/components/tactics/proofEngineReduction.ml
@@ -1023,7 +1023,7 @@ let simpl context =
                prerr_endline ("e piglio il rispettivo in :"^String.concat " " 
                  (List.map (fun x -> CicPp.ppterm x) original_args));
                (* look for args[regno] in saved_args *)
-               let wanted = List.nth args (guess_recno uri) in (* args@l ? *)
+               let wanted = List.nth (args@l) (guess_recno uri) in
                let rec aux n = function
                  | [] -> n (* DA CAPIRE *)
                  | t::_ when t = wanted -> n