eq_prop: eta contract;

--- a/src/Pure/Isar/calculation.ML	Mon Jun 26 16:54:38 2000 +0200
+++ b/src/Pure/Isar/calculation.ML	Mon Jun 26 23:59:29 2000 +0200
@@ -125,7 +125,7 @@
   let
     val facts = Proof.the_facts state;
 
-    val eq_prop = op aconv o pairself (#prop o Thm.rep_thm);
+    val eq_prop = op aconv o pairself (Pattern.eta_contract o #prop o Thm.rep_thm);
     fun differ thms thms' = not (Library.equal_lists eq_prop (thms, thms'));
 
     fun combine thms =