30 lines
916 B
Text
30 lines
916 B
Text
-- Copyright (c) 2014 Floris van Doorn. All rights reserved.
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-- Released under Apache 2.0 license as described in the file LICENSE.
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-- Author: Floris van Doorn
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import .basic .constructions
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open eq eq.ops category functor category.ops prod
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namespace yoneda
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--representable functor
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section
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variables {ob : Type} {C : category ob}
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set_option pp.universes true
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check @type_category
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section
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variables {a a' b b' : ob} (f : @hom ob C a' a) (g : @hom ob C b b')
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-- definition Hom_fun_fun :
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end
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definition Hom : Cᵒᵖ ×c C ⇒ type :=
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@functor.mk _ _ _ _ (λ a, hom (pr1 a) (pr2 a))
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(λ a b f h, pr2 f ∘ h ∘ pr1 f)
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(λ a, funext (λh, !id_left ⬝ !id_right))
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(λ a b c g f, funext (λh,
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show (pr2 g ∘ pr2 f) ∘ h ∘ (pr1 f ∘ pr1 g) = pr2 g ∘ (pr2 f ∘ h ∘ pr1 f) ∘ pr1 g, from sorry))
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--I'm lazy, waiting for automation to fill this
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end
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end yoneda
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