1{-# LANGUAGE PatternSynonyms #-} 2 3pattern A = Nothing 4 5pattern B a = Just a 6 7pattern a :+: b = (a, b) 8 9pattern Tuple a b = (a, b) 10 11pattern A = Nothing 12 13pattern B a = Just a 14 15pattern a :+: b = (a, b) 16