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diff --git a/testsuite/tests/indexed-types/should_compile/ColInference4.hs b/testsuite/tests/indexed-types/should_compile/ColInference4.hs
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+++ b/testsuite/tests/indexed-types/should_compile/ColInference4.hs
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+{-# LANGUAGE TypeFamilies #-}
+
+module ColInference  where 
+
+type family Elem c
+
+type instance Elem [e] = e
+
+class Col c where
+ isEmpty   :: c -> Bool
+ add       :: c -> Elem c -> c
+ headTail  :: c -> (Elem c,c)
+
+sawpOne c1 c2 
+	= let (x,c1') = headTail c1
+              (y,c2') = headTail c2
+	  in (add c1' y,add c1' x)