{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE DataKinds #-}
module Main (main) where
 
class C1 (a :: Bool) where
         
        c :: proxy a -> Int
 
class C2 (a :: [*])
 
class C3 (a :: [(Int, Double)])
 
class C4 (a :: (*))
 
data X (a :: [*])
x1 = undefined :: X '[Int]
x2 = undefined :: X '[Int, Double]
 
data Y (a :: (*, Bool))
y1 = undefined :: Y '(Double, True)
y2 = undefined :: Y '(Double, 'False)