diff --git a/move_to_lib.hlean b/move_to_lib.hlean index 990567a..c7ab7ff 100644 --- a/move_to_lib.hlean +++ b/move_to_lib.hlean @@ -710,205 +710,6 @@ namespace misc end misc -namespace category - - definition precategory_Group.{u} [instance] [constructor] : precategory.{u+1 u} Group := - begin - fapply precategory.mk, - { exact λG H, G →g H }, - { exact _ }, - { exact λG H K ψ φ, ψ ∘g φ }, - { exact λG, gid G }, - { intros, apply homomorphism_eq, esimp }, - { intros, apply homomorphism_eq, esimp }, - { intros, apply homomorphism_eq, esimp } - end - - - definition precategory_AbGroup.{u} [instance] [constructor] : precategory.{u+1 u} AbGroup := - begin - fapply precategory.mk, - { exact λG H, G →g H }, - { exact _ }, - { exact λG H K ψ φ, ψ ∘g φ }, - { exact λG, gid G }, - { intros, apply homomorphism_eq, esimp }, - { intros, apply homomorphism_eq, esimp }, - { intros, apply homomorphism_eq, esimp } - end - open iso - definition Group_is_iso_of_is_equiv {G H : Group} (φ : G →g H) (H : is_equiv (group_fun φ)) : - is_iso φ := - begin - fconstructor, - { exact (isomorphism.mk φ H)⁻¹ᵍ }, - { apply homomorphism_eq, rexact left_inv φ }, - { apply homomorphism_eq, rexact right_inv φ } - end - - definition Group_is_equiv_of_is_iso {G H : Group} (φ : G ⟶ H) (Hφ : is_iso φ) : - is_equiv (group_fun φ) := - begin - fapply adjointify, - { exact group_fun φ⁻¹ʰ }, - { note p := right_inverse φ, exact ap010 group_fun p }, - { note p := left_inverse φ, exact ap010 group_fun p } - end - - definition Group_iso_equiv (G H : Group) : (G ≅ H) ≃ (G ≃g H) := - begin - fapply equiv.MK, - { intro φ, induction φ with φ φi, constructor, exact Group_is_equiv_of_is_iso φ _ }, - { intro v, induction v with φ φe, constructor, exact Group_is_iso_of_is_equiv φ _ }, - { intro v, induction v with φ φe, apply isomorphism_eq, reflexivity }, - { intro φ, induction φ with φ φi, apply iso_eq, reflexivity } - end - - definition Group_props.{u} {A : Type.{u}} (v : (A → A → A) × (A → A) × A) : Prop.{u} := - begin - induction v with m v, induction v with i o, - fapply trunctype.mk, - { exact is_set A × (Πa, m a o = a) × (Πa, m o a = a) × (Πa b c, m (m a b) c = m a (m b c)) × - (Πa, m (i a) a = o) }, - { apply is_trunc_of_imp_is_trunc, intro v, induction v with H v, - have is_prop (Πa, m a o = a), from _, - have is_prop (Πa, m o a = a), from _, - have is_prop (Πa b c, m (m a b) c = m a (m b c)), from _, - have is_prop (Πa, m (i a) a = o), from _, - apply is_trunc_prod } - end - - definition Group.sigma_char2.{u} : Group.{u} ≃ - Σ(A : Type.{u}) (v : (A → A → A) × (A → A) × A), Group_props v := - begin - fapply equiv.MK, - { intro G, refine ⟨G, _⟩, induction G with G g, induction g with m s ma o om mo i mi, - repeat (fconstructor; do 2 try assumption), }, - { intro v, induction v with x v, induction v with y v, repeat induction y with x y, - repeat induction v with x v, constructor, fconstructor, repeat assumption }, - { intro v, induction v with x v, induction v with y v, repeat induction y with x y, - repeat induction v with x v, reflexivity }, - { intro v, repeat induction v with x v, reflexivity }, - end - open is_trunc - - section - local attribute group.to_has_mul group.to_has_inv [coercion] - - theorem inv_eq_of_mul_eq {A : Type} (G H : group A) (p : @mul A G ~2 @mul A H) : - @inv A G ~ @inv A H := - begin - have foo : Π(g : A), @inv A G g = (@inv A G g * g) * @inv A H g, - from λg, !mul_inv_cancel_right⁻¹, - cases G with Gs Gm Gh1 G1 Gh2 Gh3 Gi Gh4, - cases H with Hs Hm Hh1 H1 Hh2 Hh3 Hi Hh4, - change Gi ~ Hi, intro g, have p' : Gm ~2 Hm, from p, - calc - Gi g = Hm (Hm (Gi g) g) (Hi g) : foo - ... = Hm (Gm (Gi g) g) (Hi g) : by rewrite p' - ... = Hm G1 (Hi g) : by rewrite Gh4 - ... = Gm G1 (Hi g) : by rewrite p' - ... = Hi g : Gh2 - end - - theorem one_eq_of_mul_eq {A : Type} (G H : group A) - (p : @mul A (group.to_has_mul G) ~2 @mul A (group.to_has_mul H)) : - @one A (group.to_has_one G) = @one A (group.to_has_one H) := - begin - cases G with Gm Gs Gh1 G1 Gh2 Gh3 Gi Gh4, - cases H with Hm Hs Hh1 H1 Hh2 Hh3 Hi Hh4, - exact (Hh2 G1)⁻¹ ⬝ (p H1 G1)⁻¹ ⬝ Gh3 H1, - end - end - - open prod.ops - definition group_of_Group_props.{u} {A : Type.{u}} {m : A → A → A} {i : A → A} {o : A} - (H : Group_props (m, (i, o))) : group A := - ⦃group, mul := m, inv := i, one := o, is_set_carrier := H.1, - mul_one := H.2.1, one_mul := H.2.2.1, mul_assoc := H.2.2.2.1, mul_left_inv := H.2.2.2.2⦄ - - theorem Group_eq_equiv_lemma2 {A : Type} {m m' : A → A → A} {i i' : A → A} {o o' : A} - (H : Group_props (m, (i, o))) (H' : Group_props (m', (i', o'))) : - (m, (i, o)) = (m', (i', o')) ≃ (m ~2 m') := - begin - have is_set A, from pr1 H, - apply equiv_of_is_prop, - { intro p, exact apd100 (eq_pr1 p)}, - { intro p, apply prod_eq (eq_of_homotopy2 p), - apply prod_eq: esimp [Group_props] at *; esimp, - { apply eq_of_homotopy, - exact inv_eq_of_mul_eq (group_of_Group_props H) (group_of_Group_props H') p }, - { exact one_eq_of_mul_eq (group_of_Group_props H) (group_of_Group_props H') p }} - end - - open sigma.ops - - theorem Group_eq_equiv_lemma {G H : Group} - (p : (Group.sigma_char2 G).1 = (Group.sigma_char2 H).1) : - ((Group.sigma_char2 G).2 =[p] (Group.sigma_char2 H).2) ≃ - (is_mul_hom (equiv_of_eq (proof p qed : Group.carrier G = Group.carrier H))) := - begin - refine !sigma_pathover_equiv_of_is_prop ⬝e _, - induction G with G g, induction H with H h, - esimp [Group.sigma_char2] at p, induction p, - refine !pathover_idp ⬝e _, - induction g with s m ma o om mo i mi, induction h with σ μ μa ε εμ με ι μι, - exact Group_eq_equiv_lemma2 (Group.sigma_char2 (Group.mk G (group.mk s m ma o om mo i mi))).2.2 - (Group.sigma_char2 (Group.mk G (group.mk σ μ μa ε εμ με ι μι))).2.2 - end - - definition isomorphism.sigma_char (G H : Group) : (G ≃g H) ≃ Σ(e : G ≃ H), is_mul_hom e := - begin - fapply equiv.MK, - { intro φ, exact ⟨equiv_of_isomorphism φ, to_respect_mul φ⟩ }, - { intro v, induction v with e p, exact isomorphism_of_equiv e p }, - { intro v, induction v with e p, induction e, reflexivity }, - { intro φ, induction φ with φ H, induction φ, reflexivity }, - end - - definition Group_eq_equiv (G H : Group) : G = H ≃ (G ≃g H) := - begin - refine (eq_equiv_fn_eq_of_equiv Group.sigma_char2 G H) ⬝e _, - refine !sigma_eq_equiv ⬝e _, - refine sigma_equiv_sigma_right Group_eq_equiv_lemma ⬝e _, - transitivity (Σ(e : (Group.sigma_char2 G).1 ≃ (Group.sigma_char2 H).1), - @is_mul_hom _ _ _ _ (to_fun e)), apply sigma_ua, - exact !isomorphism.sigma_char⁻¹ᵉ - end - - definition to_fun_Group_eq_equiv {G H : Group} (p : G = H) - : Group_eq_equiv G H p ~ isomorphism_of_eq p := - begin - induction p, reflexivity - end - - definition Group_eq2 {G H : Group} {p q : G = H} - (r : isomorphism_of_eq p ~ isomorphism_of_eq q) : p = q := - begin - apply eq_of_fn_eq_fn (Group_eq_equiv G H), - apply isomorphism_eq, - intro g, refine to_fun_Group_eq_equiv p g ⬝ r g ⬝ (to_fun_Group_eq_equiv q g)⁻¹, - end - - definition Group_eq_equiv_Group_iso (G₁ G₂ : Group) : G₁ = G₂ ≃ G₁ ≅ G₂ := - Group_eq_equiv G₁ G₂ ⬝e (Group_iso_equiv G₁ G₂)⁻¹ᵉ - - definition category_Group.{u} : category Group.{u} := - category.mk precategory_Group - begin - intro G H, - apply is_equiv_of_equiv_of_homotopy (Group_eq_equiv_Group_iso G H), - intro p, induction p, fapply iso_eq, apply homomorphism_eq, reflexivity - end - - definition category_AbGroup : category AbGroup := - category.mk precategory_AbGroup sorry - - definition Grp.{u} [constructor] : Category := category.Mk Group.{u} category_Group - definition AbGrp [constructor] : Category := category.Mk AbGroup category_AbGroup - -end category - namespace sphere -- definition constant_sphere_map_sphere {n m : ℕ} (H : n < m) (f : S n →* S m) : diff --git a/univalent_subcategory.hlean b/univalent_subcategory.hlean index 83ad751..fca280a 100644 --- a/univalent_subcategory.hlean +++ b/univalent_subcategory.hlean @@ -4,20 +4,20 @@ open eq pointed sigma is_equiv equiv fiber algebra group is_trunc function prod namespace category -section univ_functor +section univ_subcat parameters {C : Precategory} {D : Category} (F : functor C D) (p : is_embedding F) (q : fully_faithful F) variables {a b : carrier C} include p q - definition ab_eq_equiv_iso : a = b ≃ a ≅ b := + definition eq_equiv_iso_of_fully_faithful : a = b ≃ a ≅ b := equiv.mk !ap !p -- a = b ≃ F a = F b ⬝e equiv.mk iso_of_eq !iso_of_path_equiv -- F a = F b ≃ F a ≅ F b ⬝e equiv.symm !iso_equiv_F_iso_F -- F a ≅ F b ≃ a ≅ b - definition ab_equiv_homot_iso_of_eq : @ab_eq_equiv_iso a b ~ iso_of_eq := + definition eq_equiv_iso_of_fully_faithful_homot : @eq_equiv_iso_of_fully_faithful a b ~ iso_of_eq := begin intro r, - esimp [ab_eq_equiv_iso], + esimp [eq_equiv_iso_of_fully_faithful], refine _ ⬝ left_inv (iso_equiv_F_iso_F F _ _) _, apply ap (inv (to_fun !iso_equiv_F_iso_F)), apply symm, @@ -25,12 +25,12 @@ section univ_functor apply respect_refl end - definition univ_domain : is_univalent C := + definition is_univalent_domain_of_fully_faithful_embedding : is_univalent C := begin intros, - apply homotopy_closed ab_eq_equiv_iso ab_equiv_homot_iso_of_eq + apply homotopy_closed eq_equiv_iso_of_fully_faithful eq_equiv_iso_of_fully_faithful_homot end -end univ_functor +end univ_subcat definition precategory_Group.{u} [instance] [constructor] : precategory.{u+1 u} Group := begin @@ -165,14 +165,14 @@ repeat (fconstructor; assumption), assumption, intro b, open sigma.ops -definition sigma_sigma_prod {A} {B C : A→Type} : (Σa, B a × C a) ≃ Σ p : (Σa, B a), C p.1 := +definition sigma_prod_equiv_sigma_sigma {A} {B C : A→Type} : (Σa, B a × C a) ≃ Σ p : (Σa, B a), C p.1 := sigma_equiv_sigma_right (λa, !sigma.equiv_prod⁻¹ᵉ) ⬝e !sigma_assoc_equiv -definition ab_group_group_comm (A : Type) : ab_group A ≃ Σ (g : group A), ∀ a b : A, a * b = b * a := +definition ab_group_equiv_group_comm (A : Type) : ab_group A ≃ Σ (g : group A), ∀ a b : A, a * b = b * a := begin refine !ab_group.sigma_char ⬝e _, refine sigma_equiv_sigma_right AbGroup_Group_props ⬝e _, -refine sigma_sigma_prod ⬝e _, +refine sigma_prod_equiv_sigma_sigma ⬝e _, apply equiv.symm, apply sigma_equiv_sigma !group.sigma_char, intros, induction a, reflexivity end @@ -264,9 +264,7 @@ induction p, definition to_fun_Group_eq_equiv {G H : Group} (p : G = H) : Group_eq_equiv G H p ~ isomorphism_of_eq p := - begin - induction p, reflexivity - end + begin induction p, reflexivity end definition Group_eq2 {G H : Group} {p q : G = H} (r : isomorphism_of_eq p ~ isomorphism_of_eq q) : p = q := @@ -299,7 +297,7 @@ apply is_trunc_equiv_closed, apply equiv.symm, apply group.sigma_char end -definition ab_group_to_group (A : Type) (g : ab_group A) : group A := _ +definition ab_group_to_group (A : Type) (g : ab_group A) : group A := _ definition group_comm_to_group (A : Type) : (Σ g : group A, ∀ (a b : A), a*b = b*a) → group A := pr1 @@ -314,17 +312,17 @@ induction a', fconstructor, intros, apply sigma_eq, apply is_prop.elim, intros, apply is_prop.elim, intros, apply is_prop.elim end -definition th (A : Type) : - @ab_group_to_group A ~ group_comm_to_group A ∘ ab_group_group_comm A := +definition ab_group_to_group_homot (A : Type) : + @ab_group_to_group A ~ group_comm_to_group A ∘ ab_group_equiv_group_comm A := begin intro, induction x, reflexivity end definition is_embedding_ab_group_to_group (A : Type) : is_embedding (@ab_group_to_group A) := begin -apply is_embedding_homotopy_closed_rev (th A), apply is_embedding_compose, +apply is_embedding_homotopy_closed_rev (ab_group_to_group_homot A), apply is_embedding_compose, exact is_embedding_group_comm_to_group A, apply is_embedding_of_is_equiv end -definition sigma_emb {A} {B C : A → Type} {f : Π a, B a → C a} +definition is_embedding_total_of_is_embedding_fiber {A} {B C : A → Type} {f : Π a, B a → C a} : (∀ a, is_embedding (f a)) → is_embedding (total f) := begin intro e, fapply is_embedding_of_is_prop_fiber, intro p, induction p with a c, @@ -335,22 +333,22 @@ apply is_prop_fiber_of_is_embedding, apply is_trunc_equiv_closed -1 (H⁻¹ᵉ), end -definition h2 : AbGroup_to_Group ~ Group_sigma⁻¹ ∘ total ab_group_to_group ∘ AbGroup_sigma := +definition AbGroup_to_Group_homot : AbGroup_to_Group ~ Group_sigma⁻¹ ∘ total ab_group_to_group ∘ AbGroup_sigma := begin intro g, induction g, reflexivity end definition is_embedding_AbGroup_to_Group : is_embedding AbGroup_to_Group := begin -apply is_embedding_homotopy_closed_rev h2, +apply is_embedding_homotopy_closed_rev AbGroup_to_Group_homot, apply is_embedding_compose, apply is_embedding_of_is_equiv, apply is_embedding_compose, -apply sigma_emb is_embedding_ab_group_to_group, +apply is_embedding_total_of_is_embedding_fiber is_embedding_ab_group_to_group, apply is_embedding_of_is_equiv end definition is_univalent_AbGroup : is_univalent precategory_AbGroup := begin -apply univ_domain AbGroup_to_Group is_embedding_AbGroup_to_Group, intros, apply is_equiv_id +apply is_univalent_domain_of_fully_faithful_embedding AbGroup_to_Group is_embedding_AbGroup_to_Group, intros, apply is_equiv_id end definition category_AbGroup : category AbGroup := category.mk precategory_AbGroup is_univalent_AbGroup