1 files changed, 24 insertions, 0 deletions
diff --git a/testsuite/tests/gadt/gadt-dim7.hs b/testsuite/tests/gadt/gadt-dim7.hs
new file mode 100644
index 0000000000..0ea3633fa3
--- /dev/null
+++ b/testsuite/tests/gadt/gadt-dim7.hs
@@ -0,0 +1,24 @@
+{-# LANGUAGE GADTs #-}
+
+module ShouldSucceed4 where 
+
+data Z 
+data S a 
+
+
+data Add n m r where 
+  PZero :: Add Z m m 
+  PSucc :: Add n m p -> Add (S n) m (S p) 
+
+
+data XList n a where 
+  XNil :: XList Z a  
+  XCons :: a -> XList n a -> XList (S n) a 
+
+
+-- simple safe append function 
+append :: (Add n m r) -> XList n a -> XList m a -> XList r a 
+append PZero XNil l = l 
+append (PSucc prf) (XCons x xs) l = XCons x (append prf xs l)
+
+