further 1.73 changes: added fix_direct, simplified assume interface;

--- a/src/Pure/Isar/proof_context.ML	Wed Oct 24 19:18:23 2001 +0200
+++ b/src/Pure/Isar/proof_context.ML	Wed Oct 24 19:20:02 2001 +0200
@@ -1153,5 +1153,4 @@
 
 val setup = [ProofDataData.init];
 
-
 end;