Add several helper functions.

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favonia 2017-06-06 16:57:55 -06:00
parent 52b8fee078
commit 32a6cc639d

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@ -11,25 +11,60 @@ namespace homology
(HH : → pType.{u} → AbGroup.{u})
(Hh : Π(n : ) {X Y : Type*} (f : X →* Y), HH n X →g HH n Y)
(Hid : Π(n : ) {X : Type*} (x : HH n X), Hh n (pid X) x = x)
(Hcompose : Π(n : ) {X Y Z : Type*} (g : Y →* Z) (f : X →* Y) (x : HH n X),
Hh n (g ∘* f) x = Hh n g (Hh n f x))
(Hcompose : Π(n : ) {X Y Z : Type*} (f : Y →* Z) (g : X →* Y),
Hh n (f ∘* g) ~ Hh n f ∘ Hh n g)
(Hsusp : Π(n : ) (X : Type*), HH (succ n) (psusp X) ≃g HH n X)
(Hsusp_natural : Π(n : ) {X Y : Type*} (f : X →* Y),
Hsusp n Y ∘ Hh (succ n) (psusp_functor f) ~ Hh n f ∘ Hsusp n X)
(Hexact : Π(n : ) {X Y : Type*} (f : X →* Y), is_exact_g (Hh n f) (Hh n (pcod f)))
(Hadditive : Π(n : ) {I : Set.{u}} (X : I → Type*), is_equiv (
dirsum_elim (λi, Hh n (pinl i)) : dirsum (λi, HH n (X i)) → HH n ( X))
)
(Hadditive : Π(n : ) {I : Set.{u}} (X : I → Type*), is_equiv
(dirsum_elim (λi, Hh n (pinl i)) : dirsum (λi, HH n (X i)) → HH n ( X)))
section
parameter (theory : homology_theory)
open homology_theory
definition HH_base_indep (n : ) {A : Type} (a b : A)
: HH theory n (pType.mk A a) ≃g HH theory n (pType.mk A b) :=
: HH theory n (pType.mk A a) ≃g HH theory n (pType.mk A b) :=
calc HH theory n (pType.mk A a) ≃g HH theory (int.succ n) (psusp A) : by exact (Hsusp theory n (pType.mk A a)) ⁻¹ᵍ
... ≃g HH theory n (pType.mk A b) : by exact Hsusp theory n (pType.mk A b)
definition Hh_homotopy' (n : ) {A B : Type*} (f : A → B) (p q : f pt = pt)
: Hh theory n (pmap.mk f p) ~ Hh theory n (pmap.mk f q) := λ x,
calc Hh theory n (pmap.mk f p) x
= Hh theory n (pmap.mk f p) (Hsusp theory n A ((Hsusp theory n A)⁻¹ᵍ x))
: by exact ap (Hh theory n (pmap.mk f p)) (equiv.to_right_inv (equiv_of_isomorphism (Hsusp theory n A)) x)⁻¹
... = Hsusp theory n B (Hh theory (succ n) (pmap.mk (susp.functor f) !refl) ((Hsusp theory n A)⁻¹ x))
: by exact (Hsusp_natural theory n (pmap.mk f p) ((Hsusp theory n A)⁻¹ᵍ x))⁻¹
... = Hh theory n (pmap.mk f q) (Hsusp theory n A ((Hsusp theory n A)⁻¹ x))
: by exact Hsusp_natural theory n (pmap.mk f q) ((Hsusp theory n A)⁻¹ x)
... = Hh theory n (pmap.mk f q) x
: by exact ap (Hh theory n (pmap.mk f q)) (equiv.to_right_inv (equiv_of_isomorphism (Hsusp theory n A)) x)
definition Hh_homotopy (n : ) {A B : Type*} (f g : A →* B) (h : f ~ g) : Hh theory n f ~ Hh theory n g := λ x,
calc Hh theory n f x
= Hh theory n (pmap.mk f (respect_pt f)) x : by exact ap (λ f, Hh theory n f x) (pmap.eta f)⁻¹
... = Hh theory n (pmap.mk f (h pt ⬝ respect_pt g)) x : by exact Hh_homotopy' n f (respect_pt f) (h pt ⬝ respect_pt g) x
... = Hh theory n g x : by exact ap (λ f, Hh theory n f x) (@pmap_eq _ _ (pmap.mk f (h pt ⬝ respect_pt g)) _ h (refl (h pt ⬝ respect_pt g)))
definition is_equiv_Hh (n : ) {A B : Type*} (e : A ≃* B) : is_equiv (Hh theory n e) :=
begin
fapply adjointify,
{ exact Hh theory n e⁻¹ᵉ* },
{ intro x, exact calc
Hh theory n e (Hh theory n e⁻¹ᵉ* x)
= Hh theory n (e ∘* e⁻¹ᵉ*) x : by exact (Hcompose theory n e e⁻¹ᵉ* x)⁻¹
... = Hh theory n !pid x : by exact Hh_homotopy n (e ∘* e⁻¹ᵉ*) !pid (to_right_inv e) x
... = x : by exact Hid theory n x
},
{ intro x, exact calc
Hh theory n e⁻¹ᵉ* (Hh theory n e x)
= Hh theory n (e⁻¹ᵉ* ∘* e) x : by exact (Hcompose theory n e⁻¹ᵉ* e x)⁻¹
... = Hh theory n !pid x : by exact Hh_homotopy n (e⁻¹ᵉ* ∘* e) !pid (to_left_inv e) x
... = x : by exact Hid theory n x
}
end
end
end homology