feat(library/hott) add adjointification proof up to two gaps

This commit is contained in:
Jakob von Raumer 2014-10-24 15:56:18 -04:00 committed by Leonardo de Moura
parent 354b50a1f5
commit 16a0e970f7

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@ -187,3 +187,43 @@ namespace Equiv
Equiv_mk (transport P p) (IsEquiv.transport P p)
end Equiv
namespace IsEquiv
variables {A B : Type} (f : A → B) (g : B → A)
(retr : Sect g f) (sect : Sect f g)
definition adjointify : IsEquiv f :=
let sect' := (λx, ap g (ap f ((sect x)⁻¹)) ⬝ ap g (retr (f x)) ⬝ sect x) in
let adj' := (λ (a : A),
let fgretrfa := ap f (ap g (retr (f a))) in
let fgfinvsect := ap f (ap g (ap f ((sect a)⁻¹))) in
let fgfa := f (g (f a)) in
let retrfa := retr (f a) in
have eq1 : ap f (sect a) ≈ _,
from calc ap f (sect a)
≈ idp ⬝ ap f (sect a) : !concat_1p⁻¹
... ≈ (retr (f a) ⬝ (retr (f a)⁻¹)) ⬝ ap f (sect a) : {!concat_pV⁻¹}
... ≈ ((retr (fgfa))⁻¹ ⬝ ap (f ∘ g) (retr (f a))) ⬝ ap f (sect a) : {!concat_pA1⁻¹}
... ≈ ((retr (fgfa))⁻¹ ⬝ fgretrfa) ⬝ ap f (sect a) : sorry --{!ap_compose⁻¹},
... ≈ (retr (fgfa))⁻¹ ⬝ (fgretrfa ⬝ ap f (sect a)) : !concat_pp_p,
have eq2 : ap f (sect a) ⬝ idp ≈ (retr (fgfa))⁻¹ ⬝ (fgretrfa ⬝ ap f (sect a)),
from !concat_p1 ▹ eq1,
have eq3 : idp ≈ _,
from calc idp
≈ (ap f (sect a))⁻¹ ⬝ ((retr (fgfa))⁻¹ ⬝ (fgretrfa ⬝ ap f (sect a))) : moveL_Vp _ _ _ eq2
... ≈ (ap f (sect a)⁻¹ ⬝ (retr (fgfa))⁻¹) ⬝ (fgretrfa ⬝ ap f (sect a)) : !concat_p_pp
... ≈ (ap f ((sect a)⁻¹) ⬝ (retr (fgfa))⁻¹) ⬝ (fgretrfa ⬝ ap f (sect a)) : {!ap_V⁻¹}
... ≈ ((ap f ((sect a)⁻¹) ⬝ (retr (fgfa))⁻¹) ⬝ fgretrfa) ⬝ ap f (sect a) : !concat_p_pp
... ≈ ((retrfa⁻¹ ⬝ ap (f ∘ g) (ap f ((sect a)⁻¹))) ⬝ fgretrfa) ⬝ ap f (sect a) : {!concat_pA1⁻¹}
... ≈ ((retrfa⁻¹ ⬝ fgfinvsect) ⬝ fgretrfa) ⬝ ap f (sect a) : sorry --{!ap_compose⁻¹}
... ≈ (retrfa⁻¹ ⬝ (fgfinvsect ⬝ fgretrfa)) ⬝ ap f (sect a) : {!concat_p_pp⁻¹}
... ≈ retrfa⁻¹ ⬝ ap f (ap g (ap f ((sect a)⁻¹)) ⬝ ap g (retr (f a))) ⬝ ap f (sect a) : {!ap_pp⁻¹}
... ≈ retrfa⁻¹ ⬝ (ap f (ap g (ap f ((sect a)⁻¹)) ⬝ ap g (retr (f a))) ⬝ ap f (sect a)) : !concat_p_pp⁻¹
... ≈ retrfa⁻¹ ⬝ ap f ((ap g (ap f ((sect a)⁻¹)) ⬝ ap g (retr (f a))) ⬝ sect a) : {!ap_pp⁻¹},
have eq4 : retr (f a) ≈ ap f ((ap g (ap f ((sect a)⁻¹)) ⬝ ap g (retr (f a))) ⬝ sect a),
from moveR_M1 _ _ eq3,
eq4) in
IsEquiv_mk g retr sect' adj'
end IsEquiv