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{-# LANGUAGE ExplicitForAll,GADTs #-}
-- Pattern match uses dictionaries bound higher up in the pattern
module Main where
data T = forall a. Integral a => T a
f :: T -> Bool
f (T 0) = True
f (T n) = False
g :: T -> Ordering
g (T n) | n >= 3 = if n>3 then GT else EQ
g (T n) = LT
main = do print [f (T 0), f (T 1)]
print [g (T 2), g (T 3), g (T 4)]
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