diff -r 0dacedb4a948 -r 8b13ebf3eda4 src/Pure/sign.ML
--- a/src/Pure/sign.ML	Sun Mar 18 13:51:51 2012 +0100
+++ b/src/Pure/sign.ML	Sun Mar 18 13:59:54 2012 +0100
@@ -420,7 +420,7 @@
 
 (* abbreviations *)
 
-fun add_abbrev mode (b, raw_t) thy =
+fun add_abbrev mode (b, raw_t) thy =  (* FIXME proper ctxt (?) *)
   let
     val ctxt = Syntax.init_pretty_global thy;
     val prep_tm = no_frees ctxt o Term.no_dummy_patterns o cert_term_abbrev thy;