obsolete, superseded by State panel;

--- a/src/Pure/Tools/print_operation.ML	Mon Sep 21 16:15:50 2015 +0200
+++ b/src/Pure/Tools/print_operation.ML	Mon Sep 21 16:23:48 2015 +0200
@@ -76,8 +76,4 @@
   register "theorems" "theorems of local theory or proof context"
     (Isar_Cmd.pretty_theorems false);
 
-val _ =
-  register "state" "proof state" Toplevel.pretty_state;
-
 end;
-