predefined locales "var" and "struct" (useful for sharing parameters);

--- a/src/Pure/Isar/locale.ML	Tue Aug 06 11:19:00 2002 +0200
+++ b/src/Pure/Isar/locale.ML	Tue Aug 06 11:19:52 2002 +0200
@@ -990,6 +990,8 @@
 (** locale theory setup **)
 
 val setup =
- [LocalesData.init];
+ [LocalesData.init,
+  add_locale_i true "var" empty [Elem (Fixes [(Syntax.internal "x", None, Some Syntax.NoSyn)])],
+  add_locale_i true "struct" empty [Elem (Fixes [(Syntax.internal "S", None, None)])]];
 
 end;