20 lines
740 B
Text
20 lines
740 B
Text
/-
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Copyright (c) Luke Nelson and Jared Roesch. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Luke Nelson, Jared Roesch, Sebastian Ullrich, Leonardo de Moura
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-/
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prelude
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import init.core init.function
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open function
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universes u v
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class functor (f : Type u → Type v) : Type (max (u+1) v) :=
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(map : Π {α β : Type u}, (α → β) → f α → f β)
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(map_const : Π {α β : Type u}, α → f β → f α := λ α β, map ∘ const β)
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infixr ` <$> `:100 := functor.map
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infixr ` <$ `:100 := functor.map_const
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@[reducible] def functor.map_const_rev {f : Type u → Type v} [functor f] {α β : Type u} : f β → α → f α :=
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λ a b, b <$ a
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infixr ` $> `:100 := functor.map_const_rev
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