diff -r 07f25f7d2218 -r 87e08624e209 src/Pure/Isar/method.ML
--- a/src/Pure/Isar/method.ML	Mon Feb 14 11:23:44 2000 +0100
+++ b/src/Pure/Isar/method.ML	Mon Feb 14 11:23:57 2000 +0100
@@ -201,7 +201,7 @@
 
 (* shuffle *)
 
-fun prefer i = METHOD (K (Tactic.defer_tac i THEN PRIMITIVE (Thm.permute_prems 0 1)));
+fun prefer i = METHOD (K (Tactic.defer_tac i THEN PRIMITIVE (Thm.permute_prems 0 ~1)));
 fun defer opt_i = METHOD (K (Tactic.defer_tac (if_none opt_i 1)));