1{-# LANGUAGE PatternSynonyms #-} 2{-# LANGUAGE RankNTypes #-} 3{-# LANGUAGE ViewPatterns #-} 4{-# LANGUAGE TypeOperators #-} 5{-# LANGUAGE DataKinds #-} 6module T403 where 7 8pattern (:&&:) :: () => ((k :+ 1) ~ n) => a -> HoHeList k a -> HoHeList n a 9pattern ((:&&:))xrest <- (matchNext -> Right (x, Refl, rest)) 10 11