next_block: reset_facts;

--- a/src/Pure/Isar/proof.ML	Sat Apr 15 15:00:57 2000 +0200
+++ b/src/Pure/Isar/proof.ML	Sat Apr 15 15:01:31 2000 +0200
@@ -703,7 +703,8 @@
   state
   |> assert_forward
   |> close_block
-  |> new_block;
+  |> new_block
+  |> reset_facts;
 
 
 end;