module Pandora.Paradigm.Primary.Functor.Equivalence where import Pandora.Pattern.Category (($)) import Pandora.Pattern.Functor.Contravariant (Contravariant ((>$<))) import Pandora.Paradigm.Primary.Object.Boolean (Boolean) data Equivalence a = Equivalence (a -> a -> Boolean) instance Contravariant Equivalence where f >$< Equivalence g = Equivalence $ \x y -> g (f x) (f y)