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{-# LANGUAGE FlexibleInstances, TypeFamilies #-}
import Data.Kind (Type)
class MyShow a where
myshow :: a -> String
instance MyShow a => MyShow [a] where
myshow xs = concatMap myshow xs
data T = MkT
instance MyShow T where
myshow x = "Used generic instance"
instance MyShow [T] where
myshow xs = "Used more specific instance"
type family F a :: Type
type instance F [a] = a -> F a
type instance F Int = Bool
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