--- a/src/Pure/library.ML Fri Jan 03 15:25:51 1997 +0100
+++ b/src/Pure/library.ML Mon Jan 06 17:02:09 1997 +0100
@@ -45,6 +45,13 @@
+(** stamps **)
+
+type stamp = unit ref;
+val stamp: unit -> stamp = ref;
+
+
+
(** options **)
datatype 'a option = None | Some of 'a;