diff -r c57861f709d2 -r 3c548f92e032 src/HOL/HOL.thy
--- a/src/HOL/HOL.thy	Tue Apr 29 17:13:41 1997 +0200
+++ b/src/HOL/HOL.thy	Tue Apr 29 17:14:06 1997 +0200
@@ -123,6 +123,7 @@
   "? "          :: [idts, bool] => bool             ("(3\\<exists>_./ _)" [0, 10] 10)
   "?! "         :: [idts, bool] => bool             ("(3\\<exists>!_./ _)" [0, 10] 10)
   "@case1"      :: ['a, 'b] => case_syn             ("(2_ \\<Rightarrow>/ _)" 10)
+  "@case2"      :: [case_syn, cases_syn] => cases_syn   ("_/ \\<orelse> _")
 
 syntax (symbols output)
   "*All"        :: [idts, bool] => bool             ("(3\\<forall>_./ _)" [0, 10] 10)