diff -r 646c929b6293 -r 41de937d338b src/Pure/Isar/obtain.ML
--- a/src/Pure/Isar/obtain.ML	Thu Feb 01 20:44:19 2001 +0100
+++ b/src/Pure/Isar/obtain.ML	Thu Feb 01 20:45:11 2001 +0100
@@ -11,7 +11,7 @@
 
   {
     fix thesis
-    assume that: "!!x. P x ==> thesis"
+    assume that [intro]: "!!x. P x ==> thesis"
     <chain_facts> have thesis <proof (insert that)>
   }
   fix x assm (obtained) "P x"