/- Copyright (c) 2016 Microsoft Corporation. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Author: Leonardo de Moura -/ prelude import init.category.functor universe variables u v class applicative (f : Type u → Type v) extends functor f : Type (max u+1 v):= (pure : Π {a : Type u}, a → f a) (seq : Π {a b : Type u}, f (a → b) → f a → f b) @[inline] def pure {f : Type u → Type v} [applicative f] {a : Type u} : a → f a := applicative.pure f @[inline] def seq_app {a b : Type u} {f : Type u → Type v} [applicative f] : f (a → b) → f a → f b := applicative.seq infixr ` <*> `:2 := seq_app