diff -r e3688ef49f12 -r 9d01c9a26134 src/Pure/context.ML
--- a/src/Pure/context.ML	Fri May 05 18:24:06 2000 +0200
+++ b/src/Pure/context.ML	Fri May 05 21:57:58 2000 +0200
@@ -56,7 +56,7 @@
 fun pass_theory thy f x =
   (case pass (Some thy) f x of
     (y, Some thy') => (y, thy')
-  | (_, None) => error "Missing ML theory context");
+  | (_, None) => error "Lost theory context in ML");
 
 fun save f x = setmp (get_context ()) f x;