colimit, start on encode-decode proof

This commit is contained in:
Floris van Doorn 2016-10-12 20:07:18 -04:00
parent ead2fbbd58
commit 79dea677e8
4 changed files with 210 additions and 44 deletions

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@ -16,12 +16,8 @@ namespace seq_colim
: X n →* pseq_colim f :=
pmap.mk (inclusion f) (inclusion_pt f n)
-- TODO: we need to prove this
definition pseq_colim_loop {X : → Type*} (f : Πn, X n →* X (n+1)) :
Ω (pseq_colim f) ≃* pseq_colim (λn, Ω→(f n)) :=
sorry
definition seq_diagram [reducible] (A : → Type) : Type := Π⦃n⦄, A n → A (succ n)
definition pseq_diagram [reducible] (A : → Type*) : Type := Π⦃n⦄, A n →* A (succ n)
structure Seq_diagram : Type :=
(carrier : → Type)
@ -192,8 +188,13 @@ namespace seq_colim
seq_diagram (λn, Πx, A x n) :=
λn f x, g (f x)
namespace seq_colim.ops
abbreviation ι [constructor] := @inclusion
abbreviation pι [constructor] {A} (f) {n} := @pinclusion A f n
abbreviation pι' [constructor] [parsing_only] := @pinclusion
abbreviation ι' [constructor] [parsing_only] {A} (f n) := @inclusion A f n
end seq_colim.ops
open seq_colim.ops
definition rep0_glue (k : ) (a : A 0) : ι f (rep0 f k a) = ι f a :=
begin
@ -345,6 +346,122 @@ namespace seq_colim
{ esimp, apply respect_pt }
end
definition prep0 [constructor] {A : → Type*} (f : pseq_diagram A) (k : ) : A 0 →* A k :=
pmap.mk (rep0 (λn x, f x) k)
begin induction k with k p, reflexivity, exact ap (@f k) p ⬝ !respect_pt end
definition respect_pt_prep0_succ {A : → Type*} (f : pseq_diagram A) (k : )
: respect_pt (prep0 f (succ k)) = ap (@f k) (respect_pt (prep0 f k)) ⬝ respect_pt (@f k) :=
by reflexivity
theorem prep0_succ_lemma {A : → Type*} (f : pseq_diagram A) (n : )
(p : rep0 (λn x, f x) n pt = rep0 (λn x, f x) n pt)
(q : prep0 f n (Point (A 0)) = Point (A n))
: loop_equiv_eq_closed (ap (@f n) q ⬝ respect_pt (@f n))
(ap (@f n) p) = Ω→(@f n) (loop_equiv_eq_closed q p) :=
by rewrite [▸*, con_inv, +ap_con, ap_inv, +con.assoc]
definition succ_add_tr_rep {n : } (k : ) (x : A n)
: transport A (succ_add n k) (rep f k (f x)) = rep f (succ k) x :=
begin
induction k with k p,
reflexivity,
exact tr_ap A succ (succ_add n k) _ ⬝ (fn_tr_eq_tr_fn (succ_add n k) f _)⁻¹ ⬝ ap (@f _) p,
end
definition succ_add_tr_rep_succ {n : } (k : ) (x : A n)
: succ_add_tr_rep f (succ k) x = tr_ap A succ (succ_add n k) _ ⬝
(fn_tr_eq_tr_fn (succ_add n k) f _)⁻¹ ⬝ ap (@f _) (succ_add_tr_rep f k x) :=
by reflexivity
definition code_glue_equiv [constructor] {n : } (k : ) (x y : A n)
: rep f k (f x) = rep f k (f y) ≃ rep f (succ k) x = rep f (succ k) y :=
begin
refine eq_equiv_fn_eq_of_equiv (equiv_ap A (succ_add n k)) _ _ ⬝e _,
apply eq_equiv_eq_closed,
exact succ_add_tr_rep f k x,
exact succ_add_tr_rep f k y
end
theorem code_glue_equiv_ap {n : } {k : } {x y : A n} (p : rep f k (f x) = rep f k (f y))
: code_glue_equiv f (succ k) x y (ap (@f _) p) = ap (@f _) (code_glue_equiv f k x y p) :=
begin
rewrite [▸*, +ap_con, ap_inv, +succ_add_tr_rep_succ, con_inv, inv_con_inv_right, +con.assoc],
apply whisker_left,
rewrite [- +con.assoc], apply whisker_right, rewrite [- +ap_compose'],
note s := (eq_top_of_square (natural_square
(λx, fn_tr_eq_tr_fn (succ_add n k) f x ⬝ (tr_ap A succ (succ_add n k) (f x))⁻¹) p))⁻¹,
rewrite [inv_con_inv_right at s, -con.assoc at s], exact s
end
section
parameters {X : → Type} (g : seq_diagram X) (x : X 0)
definition rep_eq_diag ⦃n : ℕ⦄ (y : X n) : seq_diagram (λk, rep g k (rep0 g n x) = rep g k y) :=
proof λk, ap (@g (n + k)) qed
definition code_incl ⦃n : ℕ⦄ (y : X n) : Type :=
seq_colim (rep_eq_diag y)
definition code [unfold 4] : seq_colim g → Type :=
seq_colim.elim_type g code_incl
begin
intro n y,
refine _ ⬝e !shift_equiv⁻¹ᵉ,
fapply seq_colim_equiv,
{ intro k, exact code_glue_equiv g k (rep0 g n x) y },
{ intro k p, exact code_glue_equiv_ap g p }
end
definition encode [unfold 5] (y : seq_colim g) (p : ι g x = y) : code y :=
transport code p (ι' _ 0 idp)
definition decode [unfold 4] (y : seq_colim g) (c : code y) : ι g x = y :=
begin
induction y,
{ esimp at c, exact sorry},
{ exact sorry }
end
definition decode_encode (y : seq_colim g) (p : ι g x = y) : decode y (encode y p) = p :=
sorry
definition encode_decode (y : seq_colim g) (c : code y) : encode y (decode y c) = c :=
sorry
definition seq_colim_eq_equiv_code [constructor] (y : seq_colim g) : (ι g x = y) ≃ code y :=
equiv.MK (encode y) (decode y) (encode_decode y) (decode_encode y)
definition seq_colim_eq {n : } (y : X n) : (ι g x = ι g y) ≃ seq_colim (rep_eq_diag y) :=
proof seq_colim_eq_equiv_code (ι g y) qed
end
definition rep0_eq_diag {X : → Type} (f : seq_diagram X) (x y : X 0)
: seq_diagram (λk, rep0 f k x = rep0 f k y) :=
proof λk, ap (@f (k)) qed
definition seq_colim_eq0 {X : → Type} (f : seq_diagram X) (x y : X 0) :
(ι f x = ι f y) ≃ seq_colim (rep0_eq_diag f x y) :=
begin
refine !seq_colim_eq ⬝e _,
fapply seq_colim_equiv,
{ intro n, exact sorry},
{ intro n p, exact sorry }
end
definition pseq_colim_loop {X : → Type*} (f : Πn, X n →* X (n+1)) :
Ω (pseq_colim f) ≃* pseq_colim (λn, Ω→(f n)) :=
begin
fapply pequiv_of_equiv,
{ refine !seq_colim_eq0 ⬝e _,
fapply seq_colim_equiv,
{ intro n, exact loop_equiv_eq_closed (respect_pt (prep0 f n)) },
{ intro n p, apply prep0_succ_lemma }},
{ exact sorry }
end
-- open succ_str
-- definition pseq_colim_succ_str_change_index' {N : succ_str} {B : N → Type*} (n : N) (m : )
-- (h : Πn, B n →* B (S n)) :

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@ -123,6 +123,7 @@ namespace spectrum
------------------------------
-- These make sense for any succ_str.
structure smap {N : succ_str} (E F : gen_prespectrum N) :=
(to_fun : Π(n:N), E n →* F n)
(glue_square : Π(n:N), glue F n ∘* to_fun n ~* Ω→ (to_fun (S n)) ∘* glue E n)
@ -243,13 +244,16 @@ namespace spectrum
definition sfiber {N : succ_str} {X Y : gen_spectrum N} (f : X →ₛ Y) : gen_spectrum N :=
spectrum.MK (λn, pfiber (f n))
(λn, pfiber_loop_space (f (S n)) ∘*ᵉ pfiber_equiv_of_square (sglue_square f n))
(λn, pfiber_loop_space (f (S n)) ∘*ᵉ pfiber_equiv_of_square _ _ (sglue_square f n))
/- the map from the fiber to the domain. The fact that the square commutes requires work -/
/- the map from the fiber to the domain -/
definition spoint {N : succ_str} {X Y : gen_spectrum N} (f : X →ₛ Y) : sfiber f →ₛ X :=
smap.mk (λn, ppoint (f n))
begin
intro n, exact sorry
intro n,
refine _ ⬝* !passoc,
refine _ ⬝* pwhisker_right _ !ap1_ppoint_phomotopy⁻¹*,
rexact (pfiber_equiv_of_square_ppoint (equiv_glue X n) (equiv_glue Y n) (sglue_square f n))⁻¹*
end
definition π_glue (X : spectrum) (n : ) : π[2] (X (2 - succ n)) ≃* π[3] (X (2 - n)) :=
@ -386,6 +390,15 @@ namespace spectrum
definition spectrify_type {N : succ_str} (X : gen_prespectrum N) (n : N) : Type* :=
pseq_colim (spectrify_type_fun X n)
/-
Let Y = spectify X. Then
Ω Y (n+1) ≡ Ω colim_k Ω^k X ((n + 1) + k)
... = colim_k Ω^{k+1} X ((n + 1) + k)
... = colim_k Ω^{k+1} X (n + (k + 1))
... = colim_k Ω^k X(n + k)
... ≡ Y n
-/
definition spectrify_pequiv {N : succ_str} (X : gen_prespectrum N) (n : N) :
spectrify_type X n ≃* Ω (spectrify_type X (S n)) :=
begin
@ -396,7 +409,7 @@ namespace spectrum
fapply pseq_colim_pequiv,
{ intro n, apply loopn_pequiv_loopn, apply pequiv_ap X, apply succ_str.add_succ },
{ intro k, apply to_homotopy,
refine !passoc⁻¹* ⬝* _, refine pwhisker_right _ (loopn_succ_in_inv_apn (succ k) _) ⬝* _,
refine !passoc⁻¹* ⬝* _, refine pwhisker_right _ (loopn_succ_in_inv_natural (succ k) _) ⬝* _,
refine !passoc ⬝* _ ⬝* !passoc⁻¹*, apply pwhisker_left,
refine !apn_pcompose⁻¹* ⬝* _ ⬝* !apn_pcompose, apply apn_phomotopy,
exact !glue_ptransport⁻¹* }

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@ -20,9 +20,9 @@ such that the evident squares commute, we can obtain a single sequence
However, in this formalization, we will only do this for k = 3, because we get more definitional
equalities in this specific case than in the general case. The reason is that we need to check
whether a term `x : fin (succ k)` represents `n`. If we do this in general using
if x = n then ... else ...
we don't get definitionally that x = n and the successor of x is 0, which means that when defining
whether a term `x : fin (succ k)` represents `k`. If we do this in general using
if x = k then ... else ...
we don't get definitionally that x = k and the successor of x is 0, which means that when defining
maps G_{n,m} -> G_{n+1,m+k-1} we need to transport along those paths, which is annoying.
So far, the splicing seems to be only needed for k = 3, so it seems to be sufficient.

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@ -7,7 +7,8 @@ open eq nat int susp pointed pmap sigma is_equiv equiv fiber algebra trunc trunc
attribute equiv.symm equiv.trans is_equiv.is_equiv_ap fiber.equiv_postcompose
fiber.equiv_precompose pequiv.to_pmap pequiv._trans_of_to_pmap ghomotopy_group_succ_in
isomorphism_of_eq pmap_bool_equiv sphere_equiv_bool psphere_pequiv_pbool [constructor]
isomorphism_of_eq pmap_bool_equiv sphere_equiv_bool psphere_pequiv_pbool fiber_eq_equiv
[constructor]
attribute is_equiv.eq_of_fn_eq_fn' [unfold 3]
attribute isomorphism._trans_of_to_hom [unfold 3]
attribute homomorphism.struct [unfold 3]
@ -90,11 +91,21 @@ namespace pi -- move to types.arrow
{ apply pmap_eq_idp}
end
end pi open pi
namespace eq
-- types.eq
definition loop_equiv_eq_closed [constructor] {A : Type} {a a' : A} (p : a = a')
: (a = a) ≃ (a' = a') :=
eq_equiv_eq_closed p p
-- init.path
definition tr_ap {A B : Type} {x y : A} (P : B → Type) (f : A → B) (p : x = y) (z : P (f x)) :
transport P (ap f p) z = transport (P ∘ f) p z :=
(tr_compose P f p z)⁻¹
definition pathover_eq_Fl' {A B : Type} {f : A → B} {a₁ a₂ : A} {b : B} (p : a₁ = a₂) (q : f a₂ = b) : (ap f p) ⬝ q =[p] q :=
by induction p; induction q; exact idpo
@ -298,16 +309,6 @@ namespace pointed
{a₁ a₂ : A} (p : a₁ = a₂) : pequiv_of_eq (ap C p) ∘* f a₁ ~* f a₂ ∘* pequiv_of_eq (ap B p) :=
pcast_commute f p
-- TODO: make the name apn_succ_phomotopy_in consistent with this
definition loopn_succ_in_inv_apn {A B : Type*} (n : ) (f : A →* B) :
Ω→[n + 1] f ∘* (loopn_succ_in A n)⁻¹ᵉ* ~* (loopn_succ_in B n)⁻¹ᵉ* ∘* Ω→[n] (Ω→ f):=
begin
apply pinv_right_phomotopy_of_phomotopy,
refine _ ⬝* !passoc⁻¹*,
apply phomotopy_pinv_left_of_phomotopy,
apply apn_succ_phomotopy_in
end
definition papply [constructor] {A : Type*} (B : Type*) (a : A) : ppmap A B →* B :=
pmap.mk (λ(f : A →* B), f a) idp
@ -337,30 +338,52 @@ namespace pointed
ppmap A B →* Ω[n] B :=
papply _ p ∘* papn_pt n A B
definition loopn_succ_in_natural {A B : Type*} {n : } (f : A →* B) :
definition loopn_succ_in_natural {A B : Type*} (n : ) (f : A →* B) :
loopn_succ_in B n ∘* Ω→[n+1] f ~* Ω→[n] (Ω→ f) ∘* loopn_succ_in A n :=
!apn_succ_phomotopy_in
definition loopn_succ_in_inv_natural {A B : Type*} {n : } (f : A →* B) :
(loopn_succ_in B n)⁻¹ᵉ* ∘* Ω→[n] (Ω→ f) ~* Ω→[n+1] f ∘* (loopn_succ_in A n)⁻¹ᵉ* :=
sorry
definition loopn_succ_in_inv_natural {A B : Type*} (n : ) (f : A →* B) :
Ω→[n + 1] f ∘* (loopn_succ_in A n)⁻¹ᵉ* ~* (loopn_succ_in B n)⁻¹ᵉ* ∘* Ω→[n] (Ω→ f):=
begin
apply pinv_right_phomotopy_of_phomotopy,
refine _ ⬝* !passoc⁻¹*,
apply phomotopy_pinv_left_of_phomotopy,
apply apn_succ_phomotopy_in
end
end pointed open pointed
namespace fiber
definition pfiber.sigma_char [constructor] {A B : Type*} (f : A →* B)
: pfiber f ≃* pointed.MK (Σa, f a = pt) ⟨pt, respect_pt f⟩ :=
pequiv_of_equiv (fiber.sigma_char f pt) idp
definition ppoint_sigma_char [constructor] {A B : Type*} (f : A →* B)
: ppoint f ~* pmap.mk pr1 idp ∘* pfiber.sigma_char f :=
!phomotopy.refl
definition pfiber_loop_space {A B : Type*} (f : A →* B) : pfiber (Ω→ f) ≃* Ω (pfiber f) :=
pequiv_of_equiv
(calc pfiber (Ω→ f) ≃ Σ(p : Point A = Point A), ap1 f p = rfl : (fiber.sigma_char (ap1 f) (Point (Ω B)))
... ≃ Σ(p : Point A = Point A), (respect_pt f) = ap f p ⬝ (respect_pt f) : (sigma_equiv_sigma_right (λp,
calc (ap1 f p = rfl) ≃ !respect_pt⁻¹ ⬝ (ap f p ⬝ !respect_pt) = rfl : equiv_eq_closed_left _ (con.assoc _ _ _)
... ≃ ap f p ⬝ (respect_pt f) = (respect_pt f) : eq_equiv_inv_con_eq_idp
... ≃ (respect_pt f) = ap f p ⬝ (respect_pt f) : eq_equiv_eq_symm))
... ≃ fiber.mk (Point A) (respect_pt f) = fiber.mk pt (respect_pt f) : fiber_eq_equiv
... ≃ Ω (pfiber f) : erfl)
(begin cases f with f p, cases A with A a, cases B with B b, esimp at p, esimp at f, induction p, reflexivity end)
(calc pfiber (Ω→ f) ≃ Σ(p : Point A = Point A), ap1 f p = rfl
: (fiber.sigma_char (ap1 f) (Point (Ω B)))
... ≃ Σ(p : Point A = Point A), (respect_pt f) = ap f p ⬝ (respect_pt f)
: (sigma_equiv_sigma_right (λp,
calc (ap1 f p = rfl) ≃ !respect_pt⁻¹ ⬝ (ap f p ⬝ !respect_pt) = rfl
: equiv_eq_closed_left _ (con.assoc _ _ _)
... ≃ ap f p ⬝ (respect_pt f) = (respect_pt f)
: eq_equiv_inv_con_eq_idp
... ≃ (respect_pt f) = ap f p ⬝ (respect_pt f)
: eq_equiv_eq_symm))
... ≃ fiber.mk (Point A) (respect_pt f) = fiber.mk pt (respect_pt f)
: fiber_eq_equiv
... ≃ Ω (pfiber f)
: erfl)
(begin cases f with f p, cases A with A a, cases B with B b, esimp at p, esimp at f,
induction p, reflexivity end)
definition pfiber_equiv_of_phomotopy {A B : Type*} {f g : A →* B} (h : f ~* g) : pfiber f ≃* pfiber g :=
definition pfiber_equiv_of_phomotopy {A B : Type*} {f g : A →* B} (h : f ~* g)
: pfiber f ≃* pfiber g :=
begin
fapply pequiv_of_equiv,
{ refine (fiber.sigma_char f pt ⬝e _ ⬝e (fiber.sigma_char g pt)⁻¹ᵉ),
@ -371,12 +394,14 @@ namespace fiber
rewrite idp_con, apply inv_con_eq_of_eq_con, symmetry, exact (to_homotopy_pt h) }
end
definition transport_fiber_equiv [constructor] {A B : Type} (f : A → B) {b1 b2 : B} (p : b1 = b2) : fiber f b1 ≃ fiber f b2 :=
definition transport_fiber_equiv [constructor] {A B : Type} (f : A → B) {b1 b2 : B} (p : b1 = b2)
: fiber f b1 ≃ fiber f b2 :=
calc fiber f b1 ≃ Σa, f a = b1 : fiber.sigma_char
... ≃ Σa, f a = b2 : sigma_equiv_sigma_right (λa, equiv_eq_closed_right (f a) p)
... ≃ fiber f b2 : fiber.sigma_char
definition pequiv_postcompose {A B B' : Type*} (f : A →* B) (g : B ≃* B') : pfiber (g ∘* f) ≃* pfiber f :=
definition pequiv_postcompose {A B B' : Type*} (f : A →* B) (g : B ≃* B')
: pfiber (g ∘* f) ≃* pfiber f :=
begin
fapply pequiv_of_equiv, esimp,
refine transport_fiber_equiv (g ∘* f) (respect_pt g)⁻¹ ⬝e fiber.equiv_postcompose f g (Point B),
@ -384,7 +409,8 @@ namespace fiber
rewrite [con.assoc, con.right_inv, con_idp, -ap_compose'], apply ap_con_eq_con
end
definition pequiv_precompose {A A' B : Type*} (f : A →* B) (g : A' ≃* A) : pfiber (f ∘* g) ≃* pfiber f :=
definition pequiv_precompose {A A' B : Type*} (f : A →* B) (g : A' ≃* A)
: pfiber (f ∘* g) ≃* pfiber f :=
begin
fapply pequiv_of_equiv, esimp,
refine fiber.equiv_precompose f g (Point B),
@ -393,12 +419,23 @@ namespace fiber
{ apply pathover_eq_Fl' }
end
definition pfiber_equiv_of_square {A B C D : Type*} {f : A →* B} {g : C →* D} {h : A ≃* C} {k : B ≃* D} (s : k ∘* f ~* g ∘* h)
: pfiber f ≃* pfiber g :=
definition pfiber_equiv_of_square {A B C D : Type*} {f : A →* B} {g : C →* D} (h : A ≃* C)
(k : B ≃* D) (s : k ∘* f ~* g ∘* h) : pfiber f ≃* pfiber g :=
calc pfiber f ≃* pfiber (k ∘* f) : pequiv_postcompose
... ≃* pfiber (g ∘* h) : pfiber_equiv_of_phomotopy s
... ≃* pfiber g : pequiv_precompose
definition ap1_ppoint_phomotopy {A B : Type*} (f : A →* B)
: Ω→ (ppoint f) ∘* pfiber_loop_space f ~* ppoint (Ω→ f) :=
begin
exact sorry
end
definition pfiber_equiv_of_square_ppoint {A B C D : Type*} {f : A →* B} {g : C →* D}
(h : A ≃* C) (k : B ≃* D) (s : k ∘* f ~* g ∘* h)
: ppoint g ∘* pfiber_equiv_of_square h k s ~* h ∘* ppoint f :=
sorry
end fiber
namespace eq --algebra.homotopy_group
@ -689,7 +726,7 @@ namespace new_sphere
{ revert A, induction n with n IH: intro A,
{ reflexivity },
{ intro f, refine ap !loopn_succ_in⁻¹ᵉ* (IH (Ω A) _ ⬝ !apn_pcompose _) ⬝ _,
exact !loopn_succ_in_inv_natural _ }}
exact !loopn_succ_in_inv_natural⁻¹* _ }}
end
end new_sphere
@ -709,4 +746,3 @@ namespace sphere
-- end
end sphere