151 lines
4.7 KiB
Text
151 lines
4.7 KiB
Text
/-
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Copyright (c) 2015 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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Module: init.hit
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Authors: Floris van Doorn
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Declaration of hits
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-/
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structure diagram [class] :=
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(Iob : Type)
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(Ihom : Type)
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(ob : Iob → Type)
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(dom cod : Ihom → Iob)
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(hom : Π(j : Ihom), ob (dom j) → ob (cod j))
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open eq diagram
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-- structure col (D : diagram) :=
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-- (incl : Π{i : Iob}, ob i)
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-- (eq_endpoint : Π{j : Ihom} (x : ob (dom j)), ob (cod j))
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-- set_option pp.universes true
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-- check @diagram
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-- check @col
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constant colimit.{u v w} : diagram.{u v w} → Type.{max u v w}
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namespace colimit
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constant inclusion : Π [D : diagram] {i : Iob}, ob i → colimit D
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abbreviation ι := @inclusion
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constant cglue : Π [D : diagram] (j : Ihom) (x : ob (dom j)), ι (hom j x) = ι x
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/-protected-/ constant rec : Π [D : diagram] {P : colimit D → Type}
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(Pincl : Π⦃i : Iob⦄ (x : ob i), P (ι x))
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(Pglue : Π(j : Ihom) (x : ob (dom j)), cglue j x ▹ Pincl (hom j x) = Pincl x)
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(y : colimit D), P y
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-- {P : my_colim f → Type} (Hinc : Π⦃n : ℕ⦄ (a : A n), P (inc f a))
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-- (Heq : Π(n : ℕ) (a : A n), inc_eq f a ▹ Hinc (f a) = Hinc a) : Πaa, P aa
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-- init_hit
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definition comp_incl [D : diagram] {P : colimit D → Type}
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(Pincl : Π⦃i : Iob⦄ (x : ob i), P (ι x))
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(Pglue : Π(j : Ihom) (x : ob (dom j)), cglue j x ▹ Pincl (hom j x) = Pincl x)
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{i : Iob} (x : ob i) : rec Pincl Pglue (ι x) = Pincl x :=
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sorry --idp
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--set_option pp.notation false
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definition comp_cglue [D : diagram] {P : colimit D → Type}
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(Pincl : Π⦃i : Iob⦄ (x : ob i), P (ι x))
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(Pglue : Π(j : Ihom) (x : ob (dom j)), cglue j x ▹ Pincl (hom j x) = Pincl x)
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{j : Ihom} (x : ob (dom j)) : apd (rec Pincl Pglue) (cglue j x) = sorry ⬝ Pglue j x ⬝ sorry :=
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--the sorry's in the statement can be removed when comp_incl is definitional
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sorry --idp
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protected definition rec_on [D : diagram] {P : colimit D → Type} (y : colimit D)
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(Pincl : Π⦃i : Iob⦄ (x : ob i), P (ι x))
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(Pglue : Π(j : Ihom) (x : ob (dom j)), cglue j x ▹ Pincl (hom j x) = Pincl x) : P y :=
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colimit.rec Pincl Pglue y
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end colimit
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open colimit bool
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namespace pushout
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section
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universe u
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parameters {TL BL TR : Type.{u}} (f : TL → BL) (g : TL → TR)
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inductive pushout_ob :=
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| tl : pushout_ob
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| bl : pushout_ob
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| tr : pushout_ob
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open pushout_ob
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definition pushout_diag [reducible] : diagram :=
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diagram.mk pushout_ob
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bool
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(λi, pushout_ob.rec_on i TL BL TR)
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(λj, bool.rec_on j tl tl)
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(λj, bool.rec_on j bl tr)
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(λj, bool.rec_on j f g)
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local notation `D` := pushout_diag
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-- open bool
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-- definition pushout_diag : diagram :=
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-- diagram.mk pushout_ob
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-- bool
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-- (λi, match i with | tl := TL | tr := TR | bl := BL end)
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-- (λj, match j with | tt := tl | ff := tl end)
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-- (λj, match j with | tt := bl | ff := tr end)
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-- (λj, match j with | tt := f | ff := g end)
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definition pushout := colimit pushout_diag
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local attribute pushout_diag [instance]
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definition inl (x : BL) : pushout :=
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@ι _ _ x
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definition inr (x : TR) : pushout :=
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@ι _ _ x
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definition coherence (x : TL) : inl (f x) = @ι _ _ x :=
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@cglue _ _ x
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definition glue (x : TL) : inl (f x) = inr (g x) :=
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@cglue _ _ x ⬝ (@cglue _ _ x)⁻¹
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set_option pp.notation false
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protected theorem rec {P : pushout → Type} --make def
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(Pinl : Π(x : BL), P (inl x))
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(Pinr : Π(x : TR), P (inr x))
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(Pglue : Π(x : TL), glue x ▹ Pinl (f x) = Pinr (g x))
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(y : pushout) : P y :=
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begin
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fapply (@colimit.rec_on _ _ y),
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{ intros [i, x], cases i,
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exact (coherence x ▹ Pinl (f x)),
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apply Pinl,
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apply Pinr},
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{ intros [j, x], cases j,
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exact idp,
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esimp [pushout_ob.cases_on],
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apply concat, rotate 1, apply (idpath (coherence x ▹ Pinl (f x))),
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apply concat, apply (ap (transport _ _)), apply (idpath (Pinr (g x))),
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apply eq_tr_of_inv_tr_eq,
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rewrite -{(transport (λ (x : pushout), P x) (inverse (coherence x)) (transport P (@cglue _ tt x) (Pinr (g x))))}con_tr,
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apply sorry
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}
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end
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example
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{P : pushout → Type}
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{Pinl : Π (x : BL), P (inl x)}
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{Pinr : Π (x : TR), P (inr x)}
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{Pglue : Π (x : TL), eq (transport (λ (x : pushout), P x) (glue x) (Pinl (f x))) (Pinr (g x))}
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{y : pushout}
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{x : @ob _ (@dom _ tt)}
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: eq (transport (λ (x : pushout), P x) (inverse (coherence x)) (transport P (@cglue _ tt x) (Pinr (g x))))
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(Pinl (f x)) :=
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begin
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rewrite -{(transport (λ (x : pushout), P x) (inverse (coherence x)) (transport P (@cglue _ tt x) (Pinr (g x))))}con_tr,
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apply sorry
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end
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exit
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