260 lines
10 KiB
Text
260 lines
10 KiB
Text
-- definitions, theorems and attributes which should be moved to files in the HoTT library
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import homotopy.sphere2 homotopy.cofiber homotopy.wedge hit.prop_trunc hit.set_quotient eq2 types.pointed2 algebra.graph algebra.category.functor.equivalence
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open eq nat int susp pointed sigma is_equiv equiv fiber algebra trunc pi group
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is_trunc function unit prod bool
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universe variable u
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namespace eq
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definition transport_lemma {A : Type} {C : A → Type} {g₁ : A → A}
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{x y : A} (p : x = y) (f : Π⦃x⦄, C x → C (g₁ x)) (z : C x) :
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transport C (ap g₁ p)⁻¹ (f (transport C p z)) = f z :=
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by induction p; reflexivity
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definition transport_lemma2 {A : Type} {C : A → Type} {g₁ : A → A}
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{x y : A} (p : x = y) (f : Π⦃x⦄, C x → C (g₁ x)) (z : C x) :
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transport C (ap g₁ p) (f z) = f (transport C p z) :=
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by induction p; reflexivity
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variables {A A' B : Type} {a a₂ a₃ : A} {p p' : a = a₂} {p₂ : a₂ = a₃}
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{a' a₂' a₃' : A'} {b b₂ : B}
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end eq open eq
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namespace nat
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-- definition rec_down_le_beta_lt (P : ℕ → Type) (s : ℕ) (H0 : Πn, s ≤ n → P n)
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-- (Hs : Πn, P (n+1) → P n) (n : ℕ) (Hn : n < s) :
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-- rec_down_le P s H0 Hs n = Hs n (rec_down_le P s H0 Hs (n+1)) :=
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-- begin
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-- revert n Hn, induction s with s IH: intro n Hn,
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-- { exfalso, exact not_succ_le_zero n Hn },
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-- { have Hn' : n ≤ s, from le_of_succ_le_succ Hn,
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-- --esimp [rec_down_le],
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-- exact sorry
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-- -- induction Hn' with s Hn IH,
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-- -- { },
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-- -- { }
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-- }
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-- end
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end nat
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-- definition ppi_eq_equiv_internal : (k = l) ≃ (k ~* l) :=
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-- calc (k = l) ≃ ppi.sigma_char P p₀ k = ppi.sigma_char P p₀ l
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-- : eq_equiv_fn_eq (ppi.sigma_char P p₀) k l
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-- ... ≃ Σ(p : k = l),
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-- pathover (λh, h pt = p₀) (respect_pt k) p (respect_pt l)
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-- : sigma_eq_equiv _ _
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-- ... ≃ Σ(p : k = l),
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-- respect_pt k = ap (λh, h pt) p ⬝ respect_pt l
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-- : sigma_equiv_sigma_right
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-- (λp, eq_pathover_equiv_Fl p (respect_pt k) (respect_pt l))
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-- ... ≃ Σ(p : k = l),
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-- respect_pt k = apd10 p pt ⬝ respect_pt l
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-- : sigma_equiv_sigma_right
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-- (λp, equiv_eq_closed_right _ (whisker_right _ (ap_eq_apd10 p _)))
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-- ... ≃ Σ(p : k ~ l), respect_pt k = p pt ⬝ respect_pt l
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-- : sigma_equiv_sigma_left' eq_equiv_homotopy
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-- ... ≃ Σ(p : k ~ l), p pt ⬝ respect_pt l = respect_pt k
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-- : sigma_equiv_sigma_right (λp, eq_equiv_eq_symm _ _)
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-- ... ≃ (k ~* l) : phomotopy.sigma_char k l
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namespace pointed
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end pointed open pointed
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namespace trunc
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open trunc_index sigma.ops
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-- TODO: redefine loopn_ptrunc_pequiv
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definition apn_ptrunc_functor (n : ℕ₋₂) (k : ℕ) {A B : Type*} (f : A →* B) :
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Ω→[k] (ptrunc_functor (n+k) f) ∘* (loopn_ptrunc_pequiv n k A)⁻¹ᵉ* ~*
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(loopn_ptrunc_pequiv n k B)⁻¹ᵉ* ∘* ptrunc_functor n (Ω→[k] f) :=
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begin
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revert n, induction k with k IH: intro n,
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{ reflexivity },
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{ exact sorry }
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end
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end trunc open trunc
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namespace sigma
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open sigma.ops
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-- open sigma.ops
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-- definition eq.rec_sigma {A : Type} {B : A → Type} {a₀ : A} {b₀ : B a₀}
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-- {P : Π(a : A) (b : B a), ⟨a₀, b₀⟩ = ⟨a, b⟩ → Type} (H : P a₀ b₀ idp) {a : A} {b : B a}
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-- (p : ⟨a₀, b₀⟩ = ⟨a, b⟩) : P a b p :=
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-- sorry
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-- definition sigma_pathover_equiv_of_is_prop {A : Type} {B : A → Type} {C : Πa, B a → Type}
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-- {a a' : A} {p : a = a'} {b : B a} {b' : B a'} {c : C a b} {c' : C a' b'}
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-- [Πa b, is_prop (C a b)] : ⟨b, c⟩ =[p] ⟨b', c'⟩ ≃ b =[p] b' :=
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-- begin
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-- fapply equiv.MK,
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-- { exact pathover_pr1 },
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-- { intro q, induction q, apply pathover_idp_of_eq, exact sigma_eq idp !is_prop.elimo },
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-- { intro q, induction q,
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-- have c = c', from !is_prop.elim, induction this,
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-- rewrite [▸*, is_prop_elimo_self (C a) c] },
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-- { esimp, generalize ⟨b, c⟩, intro x q, }
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-- end
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definition sigma_equiv_of_is_embedding_left_fun [constructor] {X Y : Type} {P : Y → Type}
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{f : X → Y} (H : Πy, P y → fiber f y) (v : Σy, P y) : Σx, P (f x) :=
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⟨fiber.point (H v.1 v.2), transport P (point_eq (H v.1 v.2))⁻¹ v.2⟩
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definition sigma_equiv_of_is_embedding_left [constructor] {X Y : Type} {P : Y → Type}
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(f : X → Y) (Hf : is_embedding f) (HP : Πx, is_prop (P (f x))) (H : Πy, P y → fiber f y) :
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(Σy, P y) ≃ Σx, P (f x) :=
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begin
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apply equiv.MK (sigma_equiv_of_is_embedding_left_fun H) (sigma_functor f (λa, id)),
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{ intro v, induction v with x p, esimp [sigma_equiv_of_is_embedding_left_fun],
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fapply sigma_eq, apply @is_injective_of_is_embedding _ _ f, exact point_eq (H (f x) p),
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apply is_prop.elimo },
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{ intro v, induction v with y p, esimp, fapply sigma_eq, exact point_eq (H y p),
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apply tr_pathover }
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end
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definition sigma_equiv_of_is_embedding_left_contr [constructor] {X Y : Type} {P : Y → Type}
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(f : X → Y) (Hf : is_embedding f) (HP : Πx, is_contr (P (f x))) (H : Πy, P y → fiber f y) :
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(Σy, P y) ≃ X :=
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sigma_equiv_of_is_embedding_left f Hf _ H ⬝e sigma_equiv_of_is_contr_right _ _
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end sigma open sigma
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namespace group
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-- definition is_equiv_isomorphism
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-- some extra instances for type class inference
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-- definition is_mul_hom_comm_homomorphism [instance] {G G' : AbGroup} (φ : G →g G')
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-- : @is_mul_hom G G' (@ab_group.to_group _ (AbGroup.struct G))
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-- (@ab_group.to_group _ (AbGroup.struct G')) φ :=
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-- homomorphism.struct φ
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-- definition is_mul_hom_comm_homomorphism1 [instance] {G G' : AbGroup} (φ : G →g G')
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-- : @is_mul_hom G G' _
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-- (@ab_group.to_group _ (AbGroup.struct G')) φ :=
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-- homomorphism.struct φ
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-- definition is_mul_hom_comm_homomorphism2 [instance] {G G' : AbGroup} (φ : G →g G')
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-- : @is_mul_hom G G' (@ab_group.to_group _ (AbGroup.struct G)) _ φ :=
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-- homomorphism.struct φ
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-- definition interchange (G : AbGroup) (a b c d : G) : (a * b) * (c * d) = (a * c) * (b * d) :=
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-- mul.comm4 a b c d
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open option
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definition add_point_AbGroup [unfold 3] {X : Type} (G : X → AbGroup) : X₊ → AbGroup
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| (some x) := G x
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| none := trivial_ab_group_lift
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-- definition trunc_isomorphism_of_equiv {A B : Type} [inf_group A] [inf_group B] (f : A ≃ B)
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-- (h : is_mul_hom f) :
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-- Group.mk (trunc 0 A) (group_trunc A) ≃g Group.mk (trunc 0 B) (group_trunc B) :=
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-- begin
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-- apply isomorphism_of_equiv (trunc_equiv_trunc 0 f), intros x x',
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-- induction x with a, induction x' with a', apply ap tr, exact h a a'
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-- end
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end group open group
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namespace fiber
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/- if we need this: do pfiber_functor_pcompose and so on first -/
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-- definition psquare_pfiber_functor [constructor] {A₁ A₂ A₃ A₄ B₁ B₂ B₃ B₄ : Type*}
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-- {f₁ : A₁ →* B₁} {f₂ : A₂ →* B₂} {f₃ : A₃ →* B₃} {f₄ : A₄ →* B₄}
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-- {g₁₂ : A₁ →* A₂} {g₃₄ : A₃ →* A₄} {g₁₃ : A₁ →* A₃} {g₂₄ : A₂ →* A₄}
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-- {h₁₂ : B₁ →* B₂} {h₃₄ : B₃ →* B₄} {h₁₃ : B₁ →* B₃} {h₂₄ : B₂ →* B₄}
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-- (H₁₂ : psquare g₁₂ h₁₂ f₁ f₂) (H₃₄ : psquare g₃₄ h₃₄ f₃ f₄)
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-- (H₁₃ : psquare g₁₃ h₁₃ f₁ f₃) (H₂₄ : psquare g₂₄ h₂₄ f₂ f₄)
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-- (G : psquare g₁₂ g₃₄ g₁₃ g₂₄) (H : psquare h₁₂ h₃₄ h₁₃ h₂₄)
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-- /- pcube H₁₂ H₃₄ H₁₃ H₂₄ G H -/ :
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-- psquare (pfiber_functor g₁₂ h₁₂ H₁₂) (pfiber_functor g₃₄ h₃₄ H₃₄)
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-- (pfiber_functor g₁₃ h₁₃ H₁₃) (pfiber_functor g₂₄ h₂₄ H₂₄) :=
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-- begin
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-- fapply phomotopy.mk,
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-- { intro x, induction x with x p, induction B₁ with B₁ b₁₀, induction f₁ with f₁ f₁₀, esimp at *,
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-- induction p, esimp [fiber_functor], },
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-- { }
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-- end
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end fiber open fiber
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namespace function
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variables {A B : Type} {f f' : A → B}
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open is_conn sigma.ops
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definition homotopy_group_isomorphism_of_is_embedding (n : ℕ) [H : is_succ n] {A B : Type*}
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(f : A →* B) [H2 : is_embedding f] : πg[n] A ≃g πg[n] B :=
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begin
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apply isomorphism.mk (homotopy_group_homomorphism n f),
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induction H with n,
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apply is_equiv_of_equiv_of_homotopy
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(ptrunc_pequiv_ptrunc 0 (loopn_pequiv_loopn_of_is_embedding (n+1) f)),
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exact sorry
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end
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definition merely_constant_pmap {A B : Type*} {f : A →* B} (H : merely_constant f) (a : A) :
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merely (f a = pt) :=
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tconcat (tconcat (H.2 a) (tinverse (H.2 pt))) (tr (respect_pt f))
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definition merely_constant_of_is_conn {A B : Type*} (f : A →* B) [is_conn 0 A] :
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merely_constant f :=
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⟨pt, is_conn.elim -1 _ (tr (respect_pt f))⟩
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end function open function
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namespace is_conn
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open unit trunc_index nat is_trunc pointed.ops sigma.ops prod.ops
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-- definition is_conn_pfiber_of_equiv_on_homotopy_groups (n : ℕ) {A B : pType.{u}} (f : A →* B)
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-- [H : is_conn 0 A]
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-- (H1 : Πk, k ≤ n → is_equiv (π→[k] f))
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-- (H2 : is_surjective (π→[succ n] f)) :
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-- is_conn n (pfiber f) :=
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-- _
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-- definition is_conn_pelim [constructor] {k : ℕ} {X : Type*} (Y : Type*) (H : is_conn k X) :
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-- (X →* connect k Y) ≃ (X →* Y) :=
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end is_conn
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namespace sphere
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-- definition constant_sphere_map_sphere {n m : ℕ} (H : n < m) (f : S n →* S m) :
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-- f ~* pconst (S n) (S m) :=
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-- begin
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-- assert H : is_contr (Ω[n] (S m)),
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-- { apply homotopy_group_sphere_le, },
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-- apply phomotopy_of_eq,
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-- apply inj !sphere_pmap_pequiv,
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-- apply @is_prop.elim
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-- end
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end sphere
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namespace paths
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variables {A : Type} {R : A → A → Type} {a₁ a₂ a₃ a₄ : A}
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definition mem_equiv_Exists (l : R a₁ a₂) (p : paths R a₃ a₄) :
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mem l p ≃ Exists (λa a' r, ⟨a₁, a₂, l⟩ = ⟨a, a', r⟩) p :=
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sorry
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end paths
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