src/Pure/Isar/isar_syn.ML
changeset 7368 6b1b6b7c1df0
parent 7308 e01aab03a2a1
child 7415 bd819d0255e1
--- a/src/Pure/Isar/isar_syn.ML	Thu Aug 26 19:01:58 1999 +0200
+++ b/src/Pure/Isar/isar_syn.ML	Thu Aug 26 19:02:21 1999 +0200
@@ -399,7 +399,8 @@
 
 val backP =
   OuterSyntax.improper_command "back" "backtracking of proof command" K.prf_script
-    (Scan.succeed (Toplevel.print o Toplevel.proof ProofHistory.back));
+    (Scan.optional (P.$$$ "!" >> K true) false >>
+      (Toplevel.print oo (Toplevel.proof o ProofHistory.back)));
 
 
 (* history *)
@@ -438,7 +439,7 @@
 
 val print_commandsP =
   OuterSyntax.improper_command "help" "print outer syntax (global)" K.diag
-    (Scan.succeed (Toplevel.imperative OuterSyntax.print_outer_syntax));
+    (Scan.succeed OuterSyntax.print_help);
 
 val print_contextP =
   OuterSyntax.improper_command "print_context" "print theory context name" K.diag