From: natile <??>
Date: Wed, 2 Oct 2002 16:28:43 +0000 (+0000)
Subject: Whithout List.hd error
X-Git-Tag: new_mathql_before_first_merge~21
X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=61872e154b77378c203e4a9b179b4067cfe7f23b;p=helm.git

Whithout List.hd error
---

diff --git a/helm/ocaml/mathql_interpreter/mqint.ml b/helm/ocaml/mathql_interpreter/mqint.ml
index 89c180abe..ba7d0713a 100644
--- a/helm/ocaml/mathql_interpreter/mqint.ml
+++ b/helm/ocaml/mathql_interpreter/mqint.ml
@@ -329,9 +329,12 @@ and exec_boole_exp c = function
 and exec_val_exp c = function
    | MathQL.Const x -> let ol = List.sort compare x in 
    			let rec edup = function
+			
 			   [] -> [] 
-			 | s::tl -> if s = (List.hd tl) then edup tl
-			            else s::(edup tl)
+			 | s::tl -> if tl <> [] then  
+			                         if s = (List.hd tl) then edup tl
+			                         else s::(edup tl)
+				    else s::[]
 	                in
 			 edup ol
    | MathQL.Record (rvar, vvar) -> List.assoc vvar (List.assoc rvar c.groups)