move results to HoTT library, and start on uniqueness of K(G, n) for n>1
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Floris van Doorn
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1 changed files with 132 additions and 206 deletions
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@ -7,234 +7,160 @@ Authors: Floris van Doorn
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Eilenberg MacLane spaces
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-/
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import homotopy.EM
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import homotopy.EM .spectrum
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open eq is_equiv equiv is_conn is_trunc unit function pointed nat group algebra trunc trunc_index
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fiber prod fin pointed
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namespace chain_complex
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open succ_str
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definition is_contr_of_is_embedding_of_is_surjective {N : succ_str} (X : chain_complex N) {n : N}
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(H : is_exact_at X (S n)) [is_embedding (cc_to_fn X n)]
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[H2 : is_surjective (cc_to_fn X (S (S (S n))))] : is_contr (X (S (S n))) :=
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begin
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apply is_contr.mk pt, intro x,
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have p : cc_to_fn X n (cc_to_fn X (S n) x) = cc_to_fn X n pt,
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from !cc_is_chain_complex ⬝ !respect_pt⁻¹,
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have q : cc_to_fn X (S n) x = pt, from is_injective_of_is_embedding p,
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induction H x q with y r,
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induction H2 y with z s,
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exact (cc_is_chain_complex X _ z)⁻¹ ⬝ ap (cc_to_fn X _) s ⬝ r
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end
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end chain_complex open chain_complex
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fiber prod fin pointed susp EM.ops
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namespace EM
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-- MOVE to connectedness
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definition is_conn_fun_to_unit_of_is_conn (n : ℕ₋₂) (A : Type) [H : is_conn n A]
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: is_conn_fun n (const A unit.star) :=
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begin
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intro u, induction u,
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exact is_conn_equiv_closed n (fiber.fiber_star_equiv A)⁻¹ᵉ _,
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end
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/- Higher EM-spaces -/
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/- Whitehead Corollaries -/
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-- to pointed
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definition pointed_eta_pequiv [constructor] (A : Type*) : A ≃* pointed.MK A pt :=
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pequiv.mk id !is_equiv_id idp
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/- every pointed map is homotopic to one of the form `pmap_of_map _ _`, up to some
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pointed equivalences -/
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definition phomotopy_pmap_of_map {A B : Type*} (f : A →* B) :
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(pointed_eta_pequiv B ⬝e* (pequiv_of_eq_pt (respect_pt f))⁻¹ᵉ*) ∘* f ∘*
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(pointed_eta_pequiv A)⁻¹ᵉ* ~* pmap_of_map f pt :=
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/- K(G, 2) is unique (see below for general case) -/
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definition loopn_EMadd1 (G : CommGroup) (n : ℕ) : Ω[succ n] (EMadd1 G n) ≃* pType_of_Group G :=
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begin
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fapply phomotopy.mk,
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{ reflexivity},
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{ esimp [pequiv.trans, pequiv.symm],
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exact !con.right_inv⁻¹ ⬝ ((!idp_con⁻¹ ⬝ !ap_id⁻¹) ◾ (!ap_id⁻¹⁻² ⬝ !idp_con⁻¹)), }
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refine _ ⬝e* loop_pEM1 G,
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cases n with n,
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{ refine !loop_ptrunc_pequiv ⬝e* _, refine ptrunc_pequiv _ _ _,
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apply is_trunc_eq, apply is_trunc_EM1},
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induction n with n IH,
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{ exact loop_pequiv_loop (loop_EM2 G)},
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refine _ ⬝e* IH,
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refine !phomotopy_group_pequiv_loop_ptrunc⁻¹ᵉ* ⬝e* _ ⬝e* !phomotopy_group_pequiv_loop_ptrunc,
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apply iterate_psusp_stability_pequiv,
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rexact add_mul_le_mul_add n 1 1
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end
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-- reorder arguments of is_equiv_compose
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-- rename whiteheads_principle to whitehead_principle
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definition whitehead_principle_pointed (n : ℕ₋₂) {A B : Type*}
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[HA : is_trunc n A] [HB : is_trunc n B] [is_conn 0 A] (f : A →* B)
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(H : Πk, is_equiv (π→*[k] f)) : is_equiv f :=
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definition EM2_map [unfold 7] {G : CommGroup} {X : Type*} (e : Ω[2] X ≃ G)
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(r : Π(p q : Ω[2] X), e (@concat (Ω X) idp idp idp p q) = e p * e q)
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[is_conn 1 X] [is_trunc 2 X] : EMadd1 G 1 → X :=
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begin
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apply whiteheads_principle n, rexact H 0,
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intro a k, revert a, apply is_conn.elim -1,
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have is_equiv (π→*[k + 1] (pointed_eta_pequiv B ⬝e* (pequiv_of_eq_pt (respect_pt f))⁻¹ᵉ*)
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∘* π→*[k + 1] f ∘* π→*[k + 1] (pointed_eta_pequiv A)⁻¹ᵉ*),
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begin
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apply is_equiv_compose (π→*[k + 1] f ∘* π→*[k + 1] (pointed_eta_pequiv A)⁻¹ᵉ*),
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apply is_equiv_compose (π→*[k + 1] (pointed_eta_pequiv A)⁻¹ᵉ*),
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all_goals apply is_equiv_homotopy_group_functor,
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end,
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refine @(is_equiv.homotopy_closed _) _ this _,
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apply to_homotopy,
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refine pwhisker_left _ !phomotopy_group_functor_compose⁻¹* ⬝* _,
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refine !phomotopy_group_functor_compose⁻¹* ⬝* _,
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apply phomotopy_group_functor_phomotopy, apply phomotopy_pmap_of_map
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change trunc 2 (susp (EM1 G)) → X, intro x,
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induction x with x, induction x with x,
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{ exact pt},
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{ exact pt},
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{ change carrier (Ω X), refine EM1_map e r x}
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end
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-- replace in homotopy_group?
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theorem trivial_homotopy_group_of_is_trunc' (A : Type*) {n k : ℕ} [is_trunc n A] (H : n < k)
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: is_contr (π[k] A) :=
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definition pEM2_pmap [constructor] {G : CommGroup} {X : Type*} (e : Ω[2] X ≃ G)
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(r : Π(p q : Ω[2] X), e (@concat (Ω X) idp idp idp p q) = e p * e q)
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[is_conn 1 X] [is_trunc 2 X] : EMadd1 G 1 →* X :=
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pmap.mk (EM2_map e r) idp
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definition loop_pEM2_pmap {G : CommGroup} {X : Type*} (e : Ω[2] X ≃ G)
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(r : Π(p q : Ω[2] X), e (@concat (Ω X) idp idp idp p q) = e p * e q)
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[is_conn 1 X] [is_trunc 2 X] :
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Ω→[2](pEM2_pmap e r) ~ e⁻¹ᵉ ∘ loopn_EMadd1 G 1 :=
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begin
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apply is_trunc_trunc_of_is_trunc,
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apply is_contr_loop_of_is_trunc,
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apply @is_trunc_of_le A n _,
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apply trunc_index.le_of_succ_le_succ,
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rewrite [succ_sub_two_succ k],
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exact of_nat_le_of_nat H,
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exact sorry
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end
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definition is_trunc_pointed_MK [instance] [priority 1100] (n : ℕ₋₂) {A : Type} (a : A)
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[H : is_trunc n A] : is_trunc n (pointed.MK A a) :=
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H
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definition is_contr_of_trivial_homotopy (n : ℕ₋₂) (A : Type) [is_trunc n A] [is_conn 0 A]
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(H : Πk a, is_contr (π[k] (pointed.MK A a))) : is_contr A :=
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-- TODO: make arguments in trivial_homotopy_group_of_is_trunc implicit
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attribute is_conn_EMadd1 is_trunc_EMadd1 [instance]
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definition pEM2_pequiv' {G : CommGroup} {X : Type*} (e : Ω[2] X ≃ G)
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(r : Π(p q : Ω[2] X), e (@concat (Ω X) idp idp idp p q) = e p * e q)
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[is_conn 1 X] [is_trunc 2 X] : EMadd1 G 1 ≃* X :=
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begin
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fapply is_trunc_is_equiv_closed_rev, { exact λa, ⋆},
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apply whiteheads_principle n,
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{ apply is_equiv_trunc_functor_of_is_conn_fun, apply is_conn_fun_to_unit_of_is_conn},
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intro a k,
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apply @is_equiv_of_is_contr,
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refine trivial_homotopy_group_of_is_trunc' _ !one_le_succ,
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end
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definition is_contr_of_trivial_homotopy_nat (n : ℕ) (A : Type) [is_trunc n A] [is_conn 0 A]
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(H : Πk a, k ≤ n → is_contr (π[k] (pointed.MK A a))) : is_contr A :=
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begin
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apply is_contr_of_trivial_homotopy n,
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intro k a, apply @lt_ge_by_cases _ _ n k,
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{ intro H', exact trivial_homotopy_group_of_is_trunc' _ H'},
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{ intro H', exact H k a H'}
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end
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definition is_contr_of_trivial_homotopy_pointed (n : ℕ₋₂) (A : Type*) [is_trunc n A]
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(H : Πk, is_contr (π[k] A)) : is_contr A :=
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begin
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have is_conn 0 A, proof H 0 qed,
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fapply is_contr_of_trivial_homotopy n A,
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intro k, apply is_conn.elim -1,
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cases A with A a, exact H k
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end
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definition is_contr_of_trivial_homotopy_nat_pointed (n : ℕ) (A : Type*) [is_trunc n A]
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(H : Πk, k ≤ n → is_contr (π[k] A)) : is_contr A :=
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begin
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have is_conn 0 A, proof H 0 !zero_le qed,
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fapply is_contr_of_trivial_homotopy_nat n A,
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intro k a H', revert a, apply is_conn.elim -1,
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cases A with A a, exact H k H'
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end
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-- replace in homotopy_group
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definition phomotopy_group_ptrunc_of_le [constructor] {k n : ℕ} (H : k ≤ n) (A : Type*) :
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π*[k] (ptrunc n A) ≃* π*[k] A :=
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calc
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π*[k] (ptrunc n A) ≃* Ω[k] (ptrunc k (ptrunc n A))
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: phomotopy_group_pequiv_loop_ptrunc k (ptrunc n A)
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... ≃* Ω[k] (ptrunc k A)
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: loopn_pequiv_loopn k (ptrunc_ptrunc_pequiv_left A (of_nat_le_of_nat H))
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... ≃* π*[k] A : (phomotopy_group_pequiv_loop_ptrunc k A)⁻¹ᵉ*
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definition is_conn_fun_of_equiv_on_homotopy_groups.{u} (n : ℕ) {A B : Type.{u}} (f : A → B)
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[is_equiv (trunc_functor 0 f)]
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(H1 : Πa k, k ≤ n → is_equiv (homotopy_group_functor k (pmap_of_map f a)))
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(H2 : Πa, is_surjective (homotopy_group_functor (succ n) (pmap_of_map f a))) : is_conn_fun n f :=
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have H2' : Πa k, k ≤ n → is_surjective (homotopy_group_functor (succ k) (pmap_of_map f a)),
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begin
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intro a k H, cases H with n' H',
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{ apply H2},
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{ apply is_surjective_of_is_equiv, apply H1, exact succ_le_succ H'}
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end,
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have H3 : Πa, is_contr (ptrunc n (pfiber (pmap_of_map f a))),
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begin
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intro a, apply is_contr_of_trivial_homotopy_nat_pointed n,
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{ intro k H, apply is_trunc_equiv_closed_rev, exact phomotopy_group_ptrunc_of_le H _,
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rexact @is_contr_of_is_embedding_of_is_surjective +3ℕ
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(LES_of_homotopy_groups (pmap_of_map f a)) (k, 0)
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(is_exact_LES_of_homotopy_groups _ _)
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proof @(is_embedding_of_is_equiv _) (H1 a k H) qed
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proof (H2' a k H) qed}
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end,
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show Πb, is_contr (trunc n (fiber f b)),
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begin
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intro b,
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note p := right_inv (trunc_functor 0 f) (tr b), revert p,
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induction (trunc_functor 0 f)⁻¹ (tr b), esimp, intro p,
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induction !tr_eq_tr_equiv p with q,
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rewrite -q, exact H3 a
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end
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-- open sigma lift
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-- definition flatten_univ.{u v} {A : Type.{u}} {B : Type.{v}} (f : A → B) :
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-- Σ(A' B' : Type.{max u v}) (f' : A' → B') (g : A ≃ A') (h : B ≃ B'), h ∘ f ~ f' ∘ g :=
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-- ⟨lift A, lift B, lift_functor f, proof equiv_lift A qed, proof equiv_lift B qed,
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-- proof sorry qed⟩
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definition is_conn_inf [reducible] (A : Type) : Type := Πn, is_conn n A
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definition is_conn_fun_inf [reducible] {A B : Type} (f : A → B) : Type := Πn, is_conn_fun n f
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/- applications to EM spaces -/
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-- TODO
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definition pEM1_pmap [constructor] {G : Group} {X : Type*} (e : Ω X ≃ G)
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(r : Πp q, e (p ⬝ q) = e p * e q) [is_conn 0 X] [is_trunc 1 X] : pEM1 G →* X :=
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begin
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apply pmap.mk (EM1_map e r),
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reflexivity,
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end
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definition loop_pEM1 [constructor] (G : Group) : Ω (pEM1 G) ≃* pType_of_Group G :=
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pequiv_of_equiv (base_eq_base_equiv G) idp
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attribute base_eq_base_equiv [constructor]
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export [unfold] groupoid_quotient
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definition loop_pEM1_pmap {G : Group} {X : Type*} (e : Ω X ≃ G)
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(r : Πp q, e (p ⬝ q) = e p * e q) [is_conn 0 X] [is_trunc 1 X] :
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Ω→(pEM1_pmap e r) ~ e⁻¹ᵉ ∘ base_eq_base_equiv G :=
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begin
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apply homotopy_of_inv_homotopy_pre (base_eq_base_equiv G),
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esimp, intro g, exact !idp_con ⬝ !elim_pth
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end
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definition pEM1_pequiv'.{u} {G : Group.{u}} {X : pType.{u}} (e : Ω X ≃ G)
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(r : Πp q, e (p ⬝ q) = e p * e q) [is_conn 0 X] [is_trunc 1 X] : pEM1 G ≃* X :=
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begin
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apply pequiv_of_pmap (pEM1_pmap e r),
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apply whitehead_principle_pointed 1,
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intro k, cases k with k,
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apply pequiv_of_pmap (pEM2_pmap e r),
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have is_conn 0 (EMadd1 G 1), from !is_conn_of_is_conn_succ,
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have is_trunc 2 (EMadd1 G 1), from !is_trunc_EMadd1,
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refine whitehead_principle_pointed 2 _ _,
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intro k, apply @nat.lt_by_cases k 2: intro H,
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{ apply @is_equiv_of_is_contr,
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all_goals (esimp; exact _)},
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{ cases k with k,
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{ apply is_equiv_trunc_functor, esimp,
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apply is_equiv.homotopy_closed, rotate 1,
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{ symmetry, exact loop_pEM1_pmap _ _},
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apply is_equiv_compose, apply to_is_equiv},
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{ apply @is_equiv_of_is_contr,
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do 2 apply trivial_homotopy_group_of_is_trunc _ _ _ !one_le_succ}}
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do 2 exact trivial_homotopy_group_of_is_conn _ (le_of_lt_succ H)},
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{ cases H, esimp, apply is_equiv_trunc_functor, esimp,
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apply is_equiv.homotopy_closed, rotate 1,
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{ symmetry, exact loop_pEM2_pmap _ _},
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apply is_equiv_compose, apply pequiv.to_is_equiv, apply to_is_equiv},
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{ apply @is_equiv_of_is_contr,
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exact trivial_homotopy_group_of_is_trunc _ H,
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apply @trivial_homotopy_group_of_is_trunc, rotate 1, exact H, exact _inst_2}
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end
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definition pEM1_pequiv.{u} {G : Group.{u}} {X : pType.{u}} (e : π₁ X ≃g G)
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[is_conn 0 X] [is_trunc 1 X] : pEM1 G ≃* X :=
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definition pEM2_pequiv {G : CommGroup} {X : Type*} (e : πg[1+1] X ≃g G)
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[is_conn 1 X] [is_trunc 2 X] : EMadd1 G 1 ≃* X :=
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begin
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apply pEM1_pequiv' (!trunc_equiv⁻¹ᵉ ⬝e equiv_of_isomorphism e),
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intro p q, esimp, exact respect_mul e (tr p) (tr q)
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have is_set (Ω[2] X), from !is_trunc_eq,
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apply pEM2_pequiv' (!trunc_equiv⁻¹ᵉ ⬝e equiv_of_isomorphism e),
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intro p q, esimp, exact to_respect_mul e (tr p) (tr q)
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end
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definition KG1_pequiv.{u} {X Y : pType.{u}} (e : π₁ X ≃g π₁ Y)
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[is_conn 0 X] [is_trunc 1 X] [is_conn 0 Y] [is_trunc 1 Y] : X ≃* Y :=
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(pEM1_pequiv e)⁻¹ᵉ* ⬝e* pEM1_pequiv !isomorphism.refl
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-- general case
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definition EMadd1_map [unfold 8] {G : CommGroup} {X : Type*} {n : ℕ} (e : Ω[succ n] X ≃ G)
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(r : Π(p q : Ω[succ n] X), e (@concat (Ω[n] X) pt pt pt p q) = e p * e q)
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[H1 : is_conn n X] [H2 : is_trunc (n.+1) X] : EMadd1 G n → X :=
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begin
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revert X e r H1 H2, induction n with n f: intro X e r H1 H2,
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{ change trunc 1 (EM1 G) → X, intro x, induction x with x, exact EM1_map e r x},
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change trunc (n.+2) (susp (iterate_psusp n (pEM1 G))) → X, intro x,
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induction x with x, induction x with x,
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{ exact pt},
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{ exact pt},
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{ change carrier (Ω X), refine f _ _ _ _ _ (tr x),
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{ refine _⁻¹ᵉ ⬝e e, apply equiv_of_pequiv, apply pequiv_of_eq, apply loop_space_succ_eq_in},
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exact abstract begin
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intro p q, refine _ ⬝ !r, apply ap e, esimp,
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apply inv_tr_eq_of_eq_tr, symmetry,
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rewrite [- + ap_inv, - + tr_compose],
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refine !loop_space_succ_eq_in_concat ⬝ _, exact !tr_inv_tr ◾ !tr_inv_tr
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end end}
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end
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definition pEMadd1_pmap [constructor] {G : CommGroup} {X : Type*} {n : ℕ} (e : Ω[succ n] X ≃ G)
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(r : Π(p q : Ω[succ n] X), e (@concat (Ω[n] X) pt pt pt p q) = e p * e q)
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[H1 : is_conn n X] [H2 : is_trunc (n.+1) X] : EMadd1 G n →* X :=
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pmap.mk (EMadd1_map e r) begin cases n with n: reflexivity end
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definition loop_pEMadd1_pmap {G : CommGroup} {X : Type*} {n : ℕ} (e : Ω[succ n] X ≃ G)
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(r : Π(p q : Ω[succ n] X), e (@concat (Ω[n] X) pt pt pt p q) = e p * e q)
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[H1 : is_conn n X] [H2 : is_trunc (n.+1) X] :
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Ω→[succ n](pEMadd1_pmap e r) ~ e⁻¹ᵉ ∘ loopn_EMadd1 G n :=
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begin
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apply homotopy_of_inv_homotopy_pre (loopn_EMadd1 G n),
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intro g, esimp at *,
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revert X e r H1 H2, induction n with n IH: intro X e r H1 H2,
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{ refine !idp_con ⬝ _, refine !ap_compose'⁻¹ ⬝ _, esimp, apply elim_pth},
|
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{ replace (succ (succ n)) with ((succ n) + 1), rewrite [apn_succ],
|
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unfold [ap1], exact sorry}
|
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--exact !idp_con ⬝ !elim_pth
|
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end
|
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|
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-- definition is_conn_of_le (n : ℕ₋₂) (A : Type) [is_conn (n.+1) A] :
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-- is_conn n A :=
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-- is_trunc_trunc_of_le A -2 (trunc_index.self_le_succ n)
|
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-- attribute is_conn_EMadd1 is_trunc_EMadd1 [instance]
|
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|
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definition pEMadd1_pequiv' {G : CommGroup} {X : Type*} {n : ℕ} (e : Ω[succ n] X ≃ G)
|
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(r : Π(p q : Ω[succ n] X), e (@concat (Ω[n] X) pt pt pt p q) = e p * e q)
|
||||
[H1 : is_conn n X] [H2 : is_trunc (n.+1) X] : EMadd1 G n ≃* X :=
|
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begin
|
||||
apply pequiv_of_pmap (pEMadd1_pmap e r),
|
||||
have is_conn 0 (EMadd1 G n), from is_conn_of_le _ (zero_le_of_nat n),
|
||||
have is_trunc (n.+1) (EMadd1 G n), from !is_trunc_EMadd1,
|
||||
refine whitehead_principle_pointed (n.+1) _ _,
|
||||
intro k, apply @nat.lt_by_cases k (succ n): intro H,
|
||||
{ apply @is_equiv_of_is_contr,
|
||||
do 2 exact trivial_homotopy_group_of_is_conn _ (le_of_lt_succ H)},
|
||||
{ cases H, esimp, apply is_equiv_trunc_functor, esimp,
|
||||
apply is_equiv.homotopy_closed, rotate 1,
|
||||
{ symmetry, exact loop_pEMadd1_pmap _ _},
|
||||
apply is_equiv_compose, apply pequiv.to_is_equiv},
|
||||
{ apply @is_equiv_of_is_contr,
|
||||
do 2 exact trivial_homotopy_group_of_is_trunc _ H}
|
||||
end
|
||||
|
||||
definition pEMadd1_pequiv {G : CommGroup} {X : Type*} {n : ℕ} (e : πg[n+1] X ≃g G)
|
||||
[H1 : is_conn n X] [H2 : is_trunc (n.+1) X] : EMadd1 G n ≃* X :=
|
||||
begin
|
||||
have is_set (Ω[succ n] X), from !is_set_loopn,
|
||||
apply pEMadd1_pequiv' (!trunc_equiv⁻¹ᵉ ⬝e equiv_of_isomorphism e),
|
||||
intro p q, esimp, exact to_respect_mul e (tr p) (tr q)
|
||||
end
|
||||
|
||||
definition EM_spectrum /-[constructor]-/ (G : CommGroup) : spectrum :=
|
||||
spectrum.Mk (K G) (λn, (loop_EM G n)⁻¹ᵉ*)
|
||||
|
||||
end EM
|
||||
-- cohomology ∥ X → K(G,n) ∥
|
||||
-- reduced cohomology ∥ X →* K(G,n) ∥
|
||||
-- but we probably want to do this for any spectrum
|
||||
|
|
|
|||
Loading…
Reference in a new issue