Fixed a bug of type unification.

--- a/src/HOL/Tools/ATP/reduce_axiomsN.ML	Sun Feb 12 21:34:28 2006 +0100
+++ b/src/HOL/Tools/ATP/reduce_axiomsN.ML	Mon Feb 13 14:05:43 2006 +0100
@@ -232,7 +232,7 @@
 fun uni_constants (c1,ctp1) (c2,ctp2) = (c1 = c2) andalso (uni_types ctp1 ctp2);
 
 fun uni_mem _ [] = false
-  | uni_mem (c,c_typ) ((c1,c_typ1)::ctyps) = (uni_constants (c,c_typ) (c1,c_typ1)) orelse (uni_mem (c,c_typ) ctyps);
+  | uni_mem (c,c_typ) ((c1,c_typ1)::ctyps) = (uni_constants (c1,c_typ1) (c,c_typ)) orelse (uni_mem (c,c_typ) ctyps);