--- /dev/null
+module ShouldSucceed where
+
+class Eq2 a where
+ deq :: a -> a -> Bool
+ foo :: a -> a
+
+instance Eq2 Int where
+ deq x y = True
+ foo x = x
+
+instance (Eq2 a) => Eq2 [a] where
+ deq (a:as) (b:bs) = if (deq a (foo b)) then (deq as (foo bs)) else False
+ foo x = x
+
+f x = deq x [1]