feat(hott): various changes in the HoTT library

This commit is contained in:
Floris van Doorn 2015-09-10 18:32:52 -04:00 committed by Leonardo de Moura
parent bd3aa9cf54
commit e84b22864f
21 changed files with 467 additions and 172 deletions

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@ -20,8 +20,8 @@ namespace category
(G : D ⇒ C)
(η : 1 ⟹ G ∘f F)
(ε : F ∘f G ⟹ 1)
(H : Π(c : C), (ε (F c)) ∘ (F (η c)) = ID (F c))
(K : Π(d : D), (G (ε d)) ∘ (η (G d)) = ID (G d))
(H : Π(c : C), ε (F c) ∘ F (η c) = ID (F c))
(K : Π(d : D), G (ε d) ∘ η (G d) = ID (G d))
abbreviation right_adjoint := @is_left_adjoint.G
abbreviation unit := @is_left_adjoint.η
@ -88,7 +88,7 @@ namespace category
[H : fully_faithful F] (c c' : C) : (c ≅ c') ≃ (F c ≅ F c') :=
begin
fapply equiv.MK,
{ exact preserve_iso F},
{ exact to_fun_iso F},
{ apply iso_of_F_iso_F},
{ exact abstract begin
intro f, induction f with f F', induction F' with g p q, apply iso_eq,
@ -119,18 +119,18 @@ namespace category
to_fun_hom G' (natural_map ε d) ∘
natural_map η' (to_fun_ob G d) = id,
{ intro d, esimp,
rewrite [category.assoc],
rewrite [assoc],
rewrite [-assoc (G (ε' d))],
esimp, rewrite [nf_fn_eq_fn_nf_pt' G' ε η d],
esimp, rewrite [category.assoc],
esimp, rewrite [-category.assoc],
esimp, rewrite [assoc],
esimp, rewrite [-assoc],
rewrite [↑functor.compose, -respect_comp G],
rewrite [nf_fn_eq_fn_nf_pt ε ε' d,nf_fn_eq_fn_nf_pt η' η (G d),▸*],
rewrite [respect_comp G],
rewrite [category.assoc,▸*,-category.assoc (G (ε d))],
rewrite [assoc,▸*,-assoc (G (ε d))],
rewrite [↑functor.compose, -respect_comp G],
rewrite [H' (G d)],
rewrite [respect_id,▸*,category.id_right],
rewrite [respect_id,▸*,id_right],
apply K},
assert lem₃ : Π (d : carrier D),
(to_fun_hom G' (natural_map ε d) ∘
@ -138,17 +138,17 @@ namespace category
to_fun_hom G (natural_map ε' d) ∘
natural_map η (to_fun_ob G' d) = id,
{ intro d, esimp,
rewrite [category.assoc, -assoc (G' (ε d))],
rewrite [assoc, -assoc (G' (ε d))],
esimp, rewrite [nf_fn_eq_fn_nf_pt' G ε' η' d],
esimp, rewrite [category.assoc], esimp, rewrite [-category.assoc],
esimp, rewrite [assoc], esimp, rewrite [-assoc],
rewrite [↑functor.compose, -respect_comp G'],
rewrite [nf_fn_eq_fn_nf_pt ε' ε d,nf_fn_eq_fn_nf_pt η η' (G' d)],
esimp,
rewrite [respect_comp G'],
rewrite [category.assoc,▸*,-category.assoc (G' (ε' d))],
rewrite [assoc,▸*,-assoc (G' (ε' d))],
rewrite [↑functor.compose, -respect_comp G'],
rewrite [H (G' d)],
rewrite [respect_id,▸*,category.id_right],
rewrite [respect_id,▸*,id_right],
apply K'},
fapply lem₁,
{ fapply functor.eq_of_pointwise_iso,
@ -165,7 +165,7 @@ namespace category
rewrite functor.hom_of_eq_eq_of_pointwise_iso,
apply nat_trans_eq, intro c, esimp,
refine !assoc⁻¹ ⬝ ap (λx, _ ∘ x) (nf_fn_eq_fn_nf_pt η η' c) ⬝ !assoc ⬝ _,
esimp, rewrite [-respect_comp G',H c,respect_id G',▸*,category.id_left]},
esimp, rewrite [-respect_comp G',H c,respect_id G',▸*,id_left]},
{ clear lem₁, refine transport_hom_of_eq_left _ ε ⬝ _,
krewrite inv_of_eq_compose_left,
rewrite functor.inv_of_eq_eq_of_pointwise_iso,
@ -175,7 +175,7 @@ namespace category
end
definition full_of_fully_faithful (H : fully_faithful F) : full F :=
λc c', is_surjective.mk (λg, tr (fiber.mk ((@(to_fun_hom F) c c')⁻¹ᶠ g) !right_inv))
λc c' g, tr (fiber.mk ((@(to_fun_hom F) c c')⁻¹ᶠ g) !right_inv)
definition faithful_of_fully_faithful (H : fully_faithful F) : faithful F :=
λc c' f f' p, is_injective_of_is_embedding p
@ -198,6 +198,36 @@ namespace category
end
/-
section
variables (η : Πc, G (F c) ≅ c) (ε : Πd, F (G d) ≅ d) -- we need some kind of naturality
include η ε
--definition inverse_of_unit_counit
private definition adj_η (c : C) : G (F c) ≅ c :=
to_fun_iso G (to_fun_iso F (η c)⁻¹ⁱ) ⬝i to_fun_iso G (ε (F c)) ⬝i η c
open iso
private theorem adjointify_adjH (c : C) :
to_hom (ε (F c)) ∘ F (to_hom (adj_η η ε c)⁻¹ⁱ) = id :=
begin
exact sorry
end
private theorem adjointify_adjK (d : D) :
G (to_hom (ε d)) ∘ to_hom (adj_η η ε (G d))⁻¹ⁱ = id :=
begin
exact sorry
end
variables (F G)
definition is_equivalence.mk : is_equivalence F :=
begin
fconstructor,
{ exact G},
{ }
end
end
definition fully_faithful_of_is_equivalence (F : C ⇒ D) [H : is_equivalence F]
: fully_faithful F :=
@ -212,19 +242,6 @@ namespace category
{ exact sorry},
end
section
variables (F G)
variables (η : G ∘f F ≅ 1) (ε : F ∘f G ≅ 1)
include η ε
--definition inverse_of_unit_counit
definition is_equivalence.mk : is_equivalence F :=
begin
exact sorry
end
end
definition fully_faithful_equiv (F : C ⇒ D) : fully_faithful F ≃ (faithful F × full F) :=
sorry

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@ -68,7 +68,6 @@ namespace category
(struct : category carrier)
attribute Category.struct [instance] [coercion]
attribute Category.to.precategory category.to_precategory [constructor]
definition Category.to_Precategory [constructor] [coercion] [reducible] (C : Category)
: Precategory :=

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@ -84,30 +84,41 @@ namespace functor
fapply @is_iso.mk, apply (F (f⁻¹)),
repeat (apply concat ; symmetry ; apply (respect_comp F) ;
apply concat ; apply (ap (λ x, to_fun_hom F x)) ;
(apply left_inverse | apply right_inverse);
(apply iso.left_inverse | apply iso.right_inverse);
apply (respect_id F) ),
end
definition respect_inv (F : C ⇒ D) {a b : C} (f : hom a b) [H : is_iso f] [H' : is_iso (F f)] :
theorem respect_inv (F : C ⇒ D) {a b : C} (f : hom a b) [H : is_iso f] [H' : is_iso (F f)] :
F (f⁻¹) = (F f)⁻¹ :=
begin
fapply @left_inverse_eq_right_inverse, apply (F f),
transitivity to_fun_hom F (f⁻¹ ∘ f),
{symmetry, apply (respect_comp F)},
{transitivity to_fun_hom F category.id,
{congruence, apply left_inverse},
{congruence, apply iso.left_inverse},
{apply respect_id}},
apply right_inverse
apply iso.right_inverse
end
attribute preserve_is_iso [instance] [priority 100]
definition preserve_iso [constructor] (F : C ⇒ D) {a b : C} (f : a ≅ b) : F a ≅ F b :=
definition to_fun_iso [constructor] (F : C ⇒ D) {a b : C} (f : a ≅ b) : F a ≅ F b :=
iso.mk (F f)
definition respect_inv' (F : C ⇒ D) {a b : C} (f : hom a b) {H : is_iso f} : F (f⁻¹) = (F f)⁻¹ :=
theorem respect_inv' (F : C ⇒ D) {a b : C} (f : hom a b) {H : is_iso f} : F (f⁻¹) = (F f)⁻¹ :=
respect_inv F f
theorem respect_refl (F : C ⇒ D) (a : C) : to_fun_iso F (iso.refl a) = iso.refl (F a) :=
iso_eq !respect_id
theorem respect_symm (F : C ⇒ D) {a b : C} (f : a ≅ b)
: to_fun_iso F f⁻¹ⁱ = (to_fun_iso F f)⁻¹ⁱ :=
iso_eq !respect_inv
theorem respect_trans (F : C ⇒ D) {a b c : C} (f : a ≅ b) (g : b ≅ c)
: to_fun_iso F (f ⬝i g) = to_fun_iso F f ⬝i to_fun_iso F g :=
iso_eq !respect_comp
protected definition assoc (H : C ⇒ D) (G : B ⇒ C) (F : A ⇒ B) :
H ∘f (G ∘f F) = (H ∘f G) ∘f F :=
!functor_mk_eq_constant (λa b f, idp)

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@ -160,6 +160,9 @@ namespace iso
protected definition trans [constructor] ⦃a b c : ob⦄ (H1 : a ≅ b) (H2 : b ≅ c) : a ≅ c :=
mk (to_hom H2 ∘ to_hom H1)
infixl `⬝i`:75 := iso.trans
postfix [parsing-only] `⁻¹ⁱ`:(max + 1) := iso.symm
definition iso_mk_eq {f f' : a ⟶ b} [H : is_iso f] [H' : is_iso f'] (p : f = f')
: iso.mk f = iso.mk f' :=
apd011 iso.mk p !is_hprop.elim

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@ -199,6 +199,14 @@ open functor
namespace yoneda
open category.set nat_trans lift
/-
These attributes make sure that the fields of the category "set" reduce to the right things
However, we don't want to have them globally, because that will unfold the composition g ∘ f
in a Category to category.category.comp g f
-/
local attribute Category.to.precategory category.to_precategory [constructor]
-- should this be defined as "yoneda_embedding Cᵒᵖ"?
definition contravariant_yoneda_embedding (C : Precategory) : Cᵒᵖ ⇒ set ^c C :=
functor_curry !hom_functor
@ -270,10 +278,10 @@ namespace yoneda
definition embedding_on_objects_yoneda_embedding (C : Category) :
is_embedding (ɏ : C → Cᵒᵖ ⇒ set) :=
begin
apply is_embedding.mk, intro c c', fapply is_equiv_of_equiv_of_homotopy,
intro c c', fapply is_equiv_of_equiv_of_homotopy,
{ exact !eq_equiv_iso ⬝e !iso_equiv_F_iso_F ⬝e !eq_equiv_iso⁻¹ᵉ},
{ intro p, induction p, esimp [equiv.trans, equiv.symm],
esimp [preserve_iso],
esimp [to_fun_iso],
rewrite -eq_of_iso_refl,
apply ap eq_of_iso, apply iso_eq, esimp,
apply nat_trans_eq, intro c',

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@ -31,9 +31,9 @@ section
(R : A → A → Type)
local abbreviation T := e_closure R
variables ⦃a a' : A⦄ {s : R a a'} {r : T a a}
variables ⦃a a' a'' : A⦄ {s : R a a'} {r : T a a} {B C : Type}
parameter {R}
protected definition e_closure.elim [unfold 8] {B : Type} {f : A → B}
protected definition e_closure.elim [unfold 8] {f : A → B}
(e : Π⦃a a' : A⦄, R a a' → f a = f a') (t : T a a') : f a = f a' :=
begin
induction t,
@ -115,5 +115,52 @@ section
intro a a' a'' t t', exact t ⬝r t',
end
definition e_closure.transport_left {f : A → B} (e : Π⦃a a' : A⦄, R a a' → f a = f a')
(t : e_closure R a a') (p : a = a'')
: e_closure.elim e (p ▸ t) = (ap f p)⁻¹ ⬝ e_closure.elim e t :=
by induction p; exact !idp_con⁻¹
definition e_closure.transport_right {f : A → B} (e : Π⦃a a' : A⦄, R a a' → f a = f a')
(t : e_closure R a a') (p : a' = a'')
: e_closure.elim e (p ▸ t) = e_closure.elim e t ⬝ (ap f p) :=
by induction p; reflexivity
definition e_closure.transport_lr {f : A → B} (e : Π⦃a a' : A⦄, R a a' → f a = f a')
(t : e_closure R a a) (p : a = a')
: e_closure.elim e (p ▸ t) = (ap f p)⁻¹ ⬝ e_closure.elim e t ⬝ (ap f p) :=
by induction p; esimp; exact !idp_con⁻¹
--dependent elimination:
variables {P : B → Type} {Q : C → Type} {f : A → B} {g : B → C} {f' : Π(a : A), P (f a)}
protected definition e_closure.elimo [unfold 6]
(p : Π⦃a a' : A⦄, R a a' → f a = f a')
(po : Π⦃a a' : A⦄ (s : R a a'), f' a =[p s] f' a')
(t : T a a') : f' a =[e_closure.elim p t] f' a' :=
begin
induction t,
exact po r,
constructor,
exact v_0⁻¹ᵒ,
exact v_0 ⬝o v_1
end
definition ap_e_closure_elimo_h [unfold 12] {g' : Πb, Q (g b)}
(p : Π⦃a a' : A⦄, R a a' → f a = f a')
--(po : Π⦃a a' : A⦄ (s : R a a'), f' a =[p s] f' a')
(po : Π⦃a a' : A⦄ (s : R a a'), g' (f a) =[p s] g' (f a'))
(q : Π⦃a a' : A⦄ (s : R a a'), apdo g' (p s) = po s)
(t : T a a') : apdo g' (e_closure.elim p t) = e_closure.elimo p po t :=
begin
induction t,
apply q,
reflexivity,
esimp [e_closure.elim],
exact apdo_inv g' (e_closure.elim p r) ⬝ v_0⁻²ᵒ,
exact apdo_con g' (e_closure.elim p r) (e_closure.elim p r') ⬝ (v_0 ◾o v_1)
end
end
end relation

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@ -19,7 +19,7 @@ The rows indicate the chapters, the columns the sections.
| Ch 2 | + | + | + | + | . | + | + | + | + | + | + | + | + | + | + |
| Ch 3 | + | + | + | + | ½ | + | + | - | + | . | + | | | | |
| Ch 4 | - | + | - | + | . | + | - | - | + | | | | | | |
| Ch 5 | - | . | - | - | - | . | . | ½ | | | | | | | |
| Ch 5 | - | . | ½ | - | - | . | . | ½ | | | | | | | |
| Ch 6 | . | + | + | + | + | ½ | ½ | ¼ | ¼ | ¼ | ¾ | - | . | | |
| Ch 7 | + | + | + | - | - | - | - | | | | | | | | |
| Ch 8 | ¾ | - | - | - | - | - | - | - | - | - | | | | | |
@ -27,7 +27,7 @@ The rows indicate the chapters, the columns the sections.
| Ch 10 | - | - | - | - | - | | | | | | | | | | |
| Ch 11 | - | - | - | - | - | - | | | | | | | | | |
Things not in the book:
Theorems and definitions in the library which are not in the book:
* One major difference is that in this library we heavily use pathovers, so we need less theorems about transports, but instead corresponding theorems about pathovers. These are in [init.pathover](init/pathover.hlean). For higher paths there are [squares](cubical/square.hlean), [squareovers](cubical/squareover.hlean), and the rudiments of [cubes](cubical/cube.hlean) and [cubeovers](cubical/cubeover.hlean).
@ -99,7 +99,7 @@ Chapter 5: Induction
- 5.1 (Introduction to inductive types): not formalized
- 5.2 (Uniqueness of inductive types): no formalizable content
- 5.3 (W-types): related: [types.W](types/W.hlean)
- 5.3 (W-types): [types.W](types/W.hlean) defines W-types.
- 5.4 (Inductive types are initial algebras): not formalized
- 5.5 (Homotopy-inductive types): not formalized
- 5.6 (The general syntax of inductive definitions): no formalizable content

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@ -64,7 +64,7 @@ namespace eq
square p p₁₂ p₀₁ p₂₁ :=
by induction r; exact s₁₁
definition vconcat_eq [unfold 11] {p : a₀₂ = a₂₂} (s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁) (r : p₁₂ = p) :
definition vconcat_eq [unfold 12] {p : a₀₂ = a₂₂} (s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁) (r : p₁₂ = p) :
square p₁₀ p p₀₁ p₂₁ :=
by induction r; exact s₁₁
@ -72,11 +72,10 @@ namespace eq
square p₁₀ p₁₂ p p₂₁ :=
by induction r; exact s₁₁
definition hconcat_eq [unfold 11] {p : a₂₀ = a₂₂} (s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁) (r : p₂₁ = p) :
definition hconcat_eq [unfold 12] {p : a₂₀ = a₂₂} (s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁) (r : p₂₁ = p) :
square p₁₀ p₁₂ p₀₁ p :=
by induction r; exact s₁₁
infix `⬝h`:75 := hconcat
infix `⬝v`:75 := vconcat
infix `⬝hp`:75 := hconcat_eq

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@ -32,7 +32,9 @@ namespace eq
/-a₀₂-/ {p₁₂ : a₀₂ = a₂₂} /-a₂₂-/ {p₃₂ : a₂₂ = a₄₂} /-a₄₂-/
{p₀₃ : a₀₂ = a₀₄} /-s₁₃-/ {p₂₃ : a₂₂ = a₂₄} /-s₃₃-/ {p₄₃ : a₄₂ = a₄₄}
/-a₀₄-/ {p₁₄ : a₀₄ = a₂₄} /-a₂₄-/ {p₃₄ : a₂₄ = a₄₄} /-a₄₄-/
{s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁}
{s₁₁ : square p₁₀ p₁₂ p₀₁ p₂₁} {s₃₁ : square p₃₀ p₃₂ p₂₁ p₄₁}
{s₁₃ : square p₁₂ p₁₄ p₀₃ p₂₃} {s₃₃ : square p₃₂ p₃₄ p₂₃ p₄₃}
{b₀₀ : B a₀₀} {b₂₀ : B a₂₀} {b₄₀ : B a₄₀}
{b₀₂ : B a₀₂} {b₂₂ : B a₂₂} {b₄₂ : B a₄₂}
{b₀₄ : B a₀₄} {b₂₄ : B a₂₄} {b₄₄ : B a₄₄}
@ -58,12 +60,66 @@ namespace eq
definition vdeg_squareover {q₁₀' : b₀₀ =[p₁₀] b₂₀} (r : q₁₀ = q₁₀')
: squareover B vrfl q₁₀ q₁₀' idpo idpo :=
by induction r;exact vrflo
by induction r; exact vrflo
definition hdeg_squareover {q₀₁' : b₀₀ =[p₀₁] b₀₂} (r : q₀₁ = q₀₁')
: squareover B hrfl idpo idpo q₀₁ q₀₁' :=
by induction r; exact hrflo
definition hconcato
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (t₃₁ : squareover B s₃₁ q₃₀ q₃₂ q₂₁ q₄₁)
: squareover B (hconcat s₁₁ s₃₁) (q₁₀ ⬝o q₃₀) (q₁₂ ⬝o q₃₂) q₀₁ q₄₁ :=
by induction t₃₁; exact t₁₁
definition vconcato
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (t₁₃ : squareover B s₁₃ q₁₂ q₁₄ q₀₃ q₂₃)
: squareover B (vconcat s₁₁ s₁₃) q₁₀ q₁₄ (q₀₁ ⬝o q₀₃) (q₂₁ ⬝o q₂₃) :=
by induction t₁₃; exact t₁₁
definition hinverseo (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁)
: squareover B (hinverse s₁₁) q₁₀⁻¹ᵒ q₁₂⁻¹ᵒ q₂₁ q₀₁ :=
by induction t₁₁; constructor
definition vinverseo (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁)
: squareover B (vinverse s₁₁) q₁₂ q₁₀ q₀₁⁻¹ᵒ q₂₁⁻¹ᵒ :=
by induction t₁₁; constructor
definition eq_vconcato {q : b₀₀ =[p₁₀] b₂₀}
(r : q = q₁₀) (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) : squareover B s₁₁ q q₁₂ q₀₁ q₂₁ :=
by induction r; exact t₁₁
definition vconcato_eq {q : b₀₂ =[p₁₂] b₂₂}
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (r : q₁₂ = q) : squareover B s₁₁ q₁₀ q q₀₁ q₂₁ :=
by induction r; exact t₁₁
definition eq_hconcato {q : b₀₀ =[p₀₁] b₀₂}
(r : q = q₀₁) (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) : squareover B s₁₁ q₁₀ q₁₂ q q₂₁ :=
by induction r; exact t₁₁
definition hconcato_eq {q : b₂₀ =[p₂₁] b₂₂}
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (r : q₂₁ = q) : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q :=
by induction r; exact t₁₁
definition pathover_vconcato {p : a₀₀ = a₂₀} {sp : p = p₁₀} {q : b₀₀ =[p] b₂₀}
(r : change_path sp q = q₁₀) (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁)
: squareover B (sp ⬝pv s₁₁) q q₁₂ q₀₁ q₂₁ :=
by induction sp; induction r; exact t₁₁
definition vconcato_pathover {p : a₀₂ = a₂₂} {sp : p₁₂ = p} {q : b₀₂ =[p] b₂₂}
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (r : change_path sp q₁₂ = q)
: squareover B (s₁₁ ⬝vp sp) q₁₀ q q₀₁ q₂₁ :=
by induction sp; induction r; exact t₁₁
definition pathover_hconcato {p : a₀₀ = a₀₂} {sp : p = p₀₁} {q : b₀₀ =[p] b₀₂}
(r : change_path sp q = q₀₁) (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) :
squareover B (sp ⬝ph s₁₁) q₁₀ q₁₂ q q₂₁ :=
by induction sp; induction r; exact t₁₁
definition hconcato_pathover {p : a₂₀ = a₂₂} {sp : p₂₁ = p} {q : b₂₀ =[p] b₂₂}
(t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) (r : change_path sp q₂₁ = q) :
squareover B (s₁₁ ⬝hp sp) q₁₀ q₁₂ q₀₁ q :=
by induction sp; induction r; exact t₁₁
-- relating squareovers to squares
definition square_of_squareover (t₁₁ : squareover B s₁₁ q₁₀ q₁₂ q₀₁ q₂₁) :
square (!con_tr ⬝ ap (λa, p₂₁ ▸ a) (tr_eq_of_pathover q₁₀))

View file

@ -12,8 +12,8 @@ open function
namespace eq
variables {A B C : Type} {f : A → B} {a a' a₁ a₂ a₃ a₄ : A} {b b' : B}
theorem ap_weakly_constant_eq (p : Πx, f x = b) (q : a = a') :
ap_weakly_constant p q =
theorem ap_is_constant_eq (p : Πx, f x = b) (q : a = a') :
ap_is_constant p q =
eq_con_inv_of_con_eq ((eq_of_square (square_of_pathover (apdo p q)))⁻¹ ⬝
whisker_left (p a) (ap_constant q b)) :=
begin
@ -48,10 +48,10 @@ namespace eq
idp :=
by cases p;apply vrefl
theorem ap_ap_weakly_constant {A B C : Type} (g : B → C) {f : A → B} {b : B}
theorem ap_ap_is_constant {A B C : Type} (g : B → C) {f : A → B} {b : B}
(p : Πx, f x = b) {x y : A} (q : x = y) :
square (ap (ap g) (ap_weakly_constant p q))
(ap_weakly_constant (λa, ap g (p a)) q)
square (ap (ap g) (ap_is_constant p q))
(ap_is_constant (λa, ap g (p a)) q)
(ap_compose g f q)⁻¹
(!ap_con ⬝ whisker_left _ !ap_inv) :=
begin

View file

@ -7,39 +7,48 @@ Ported from Coq HoTT
Theorems about embeddings and surjections
-/
import hit.trunc types.equiv
import hit.trunc types.equiv cubical.square
open equiv sigma sigma.ops eq trunc is_trunc pi is_equiv fiber prod
variables {A B : Type} {f : A → B} {b : B}
variables {A B : Type} (f : A → B) {b : B}
structure is_embedding [class] (f : A → B) :=
(elim : Π(a a' : A), is_equiv (ap f : a = a' → f a = f a'))
definition is_embedding [class] (f : A → B) := Π(a a' : A), is_equiv (ap f : a = a' → f a = f a')
structure is_surjective [class] (f : A → B) :=
(elim : Π(b : B), ∥ fiber f b ∥)
definition is_surjective [class] (f : A → B) := Π(b : B), ∥ fiber f b ∥
structure is_split_surjective [class] (f : A → B) :=
(elim : Π(b : B), fiber f b)
definition is_split_surjective [class] (f : A → B) := Π(b : B), fiber f b
structure is_retraction [class] (f : A → B) :=
(sect : B → A)
(right_inverse : Π(b : B), f (sect b) = b)
definition is_weakly_constant [class] (f : A → B) (a a' : A) := f a = f a'
structure is_section [class] (f : A → B) :=
(retr : B → A)
(left_inverse : Π(a : A), retr (f a) = a)
definition is_weakly_constant [class] (f : A → B) := Π(a a' : A), f a = f a'
structure is_constant [class] (f : A → B) :=
(pt : B)
(eq : Π(a : A), f a = pt)
structure conditionally_constant [class] (f : A → B) :=
structure is_conditionally_constant [class] (f : A → B) :=
(g : ∥A∥ → B)
(eq : Π(a : A), f a = g (tr a))
namespace function
attribute is_embedding.elim [instance]
abbreviation sect [unfold 4] := @is_retraction.sect
abbreviation right_inverse [unfold 4] := @is_retraction.right_inverse
abbreviation retr [unfold 4] := @is_section.retr
abbreviation left_inverse [unfold 4] := @is_section.left_inverse
definition is_equiv_ap_of_embedding [instance] [H : is_embedding f] (a a' : A)
: is_equiv (ap f : a = a' → f a = f a') :=
H a a'
variable {f}
definition is_injective_of_is_embedding [reducible] [H : is_embedding f] {a a' : A}
: f a = f a' → a = a' :=
(ap f)⁻¹
@ -47,29 +56,18 @@ namespace function
definition is_embedding_of_is_injective [HA : is_hset A] [HB : is_hset B]
(H : Π(a a' : A), f a = f a' → a = a') : is_embedding f :=
begin
fapply is_embedding.mk,
intro a a',
fapply adjointify,
{exact (H a a')},
{intro p, apply is_hset.elim},
{intro p, apply is_hset.elim}
end
variable (f)
definition is_hprop_is_embedding [instance] (f : A → B) : is_hprop (is_embedding f) :=
begin
have H : (Π(a a' : A), is_equiv (@ap A B f a a')) ≃ is_embedding f,
begin
fapply equiv.MK,
{exact is_embedding.mk},
{intro h, cases h, exact elim},
{intro h, cases h, apply idp},
{intro p, apply idp},
end,
apply is_trunc_equiv_closed,
exact H,
end
definition is_hprop_is_embedding [instance] : is_hprop (is_embedding f) :=
by unfold is_embedding; exact _
definition is_hprop_fiber_of_is_embedding (f : A → B) [H : is_embedding f] (b : B) :
definition is_hprop_fiber_of_is_embedding [H : is_embedding f] (b : B) :
is_hprop (fiber f b) :=
begin
apply is_hprop.mk, intro v w,
@ -79,65 +77,72 @@ namespace function
{ esimp [is_injective_of_is_embedding], symmetry, apply right_inv}
end
variable {f}
definition is_surjective_rec_on {P : Type} (H : is_surjective f) (b : B) [Pt : is_hprop P]
(IH : fiber f b → P) : P :=
trunc.rec_on (is_surjective.elim f b) IH
trunc.rec_on (H b) IH
variable (f)
definition is_surjective_of_is_split_surjective [instance] [H : is_split_surjective f]
: is_surjective f :=
is_surjective.mk (λb, tr (is_split_surjective.elim f b))
λb, tr (H b)
definition is_hprop_is_surjective [instance] (f : A → B) : is_hprop (is_surjective f) :=
definition is_hprop_is_surjective [instance] : is_hprop (is_surjective f) :=
by unfold is_surjective; exact _
definition is_weakly_constant_ap [instance] [H : is_weakly_constant f] (a a' : A) :
is_weakly_constant (ap f : a = a' → f a = f a') :=
take p q : a = a',
have Π{b c : A} {r : b = c}, (H a b)⁻¹ ⬝ H a c = ap f r, from
(λb c r, eq.rec_on r !con.left_inv),
this⁻¹ ⬝ this
definition is_constant_ap [unfold 4] [instance] [H : is_constant f] (a a' : A)
: is_constant (ap f : a = a' → f a = f a') :=
begin
have H : (Π(b : B), merely (fiber f b)) ≃ is_surjective f,
begin
fapply equiv.MK,
{exact is_surjective.mk},
{intro h, cases h, exact elim},
{intro h, cases h, apply idp},
{intro p, apply idp},
end,
apply is_trunc_equiv_closed,
exact H,
induction H with b q,
fapply is_constant.mk,
{ exact q a ⬝ (q a')⁻¹},
{ intro p, induction p, exact !con.right_inv⁻¹}
end
-- definition is_hprop_is_split_surjective [instance] (f : A → B) : is_hprop (is_split_surjective f) :=
-- begin
-- have H : (Π(b : B), fiber f b) ≃ is_split_surjective f,
-- begin
-- fapply equiv.MK,
-- {exact is_split_surjective.mk},
-- {intro h, cases h, exact elim},
-- {intro h, cases h, apply idp},
-- {intro p, apply idp},
-- end,
-- apply is_trunc_equiv_closed,
-- exact H,
-- apply is_trunc_pi, intro b,
-- apply is_trunc_equiv_closed_rev,
-- apply fiber.sigma_char,
-- end
definition is_contr_is_retraction [instance] [H : is_equiv f] : is_contr (is_retraction f) :=
begin
have H2 : (Σ(g : B → A), Πb, f (g b) = b) ≃ is_retraction f,
begin
fapply equiv.MK,
{intro x, induction x with g p, constructor, exact p},
{intro h, induction h, apply sigma.mk, assumption},
{intro h, induction h, reflexivity},
{intro x, induction x, reflexivity},
end,
apply is_trunc_equiv_closed, exact H2,
apply is_equiv.is_contr_right_inverse
end
-- definition is_hprop_is_retraction [instance] (f : A → B) : is_hprop (is_retraction f) :=
-- begin
-- have H : (Σ(g : B → A), Πb, f (g b) = b) ≃ is_retraction f,
-- begin
-- fapply equiv.MK,
-- {intro x, induction x with g p, constructor, exact p},
-- {intro h, induction h, apply sigma.mk, assumption},
-- {intro h, induction h, reflexivity},
-- {intro x, induction x, reflexivity},
-- end,
-- apply is_trunc_equiv_closed,
-- exact H,
-- apply is_trunc_of_imp_is_trunc, intro x, induction x with g p,
-- apply is_contr_right_inverse
-- end
definition is_contr_is_section [instance] [H : is_equiv f] : is_contr (is_section f) :=
begin
have H2 : (Σ(g : B → A), Πa, g (f a) = a) ≃ is_section f,
begin
fapply equiv.MK,
{intro x, induction x with g p, constructor, exact p},
{intro h, induction h, apply sigma.mk, assumption},
{intro h, induction h, reflexivity},
{intro x, induction x, reflexivity},
end,
apply is_trunc_equiv_closed, exact H2,
fapply is_trunc_equiv_closed,
{apply sigma_equiv_sigma_id, intro g, apply eq_equiv_homotopy},
fapply is_trunc_equiv_closed,
{apply fiber.sigma_char},
fapply is_contr_fiber_of_is_equiv,
exact to_is_equiv (arrow_equiv_arrow_left_rev A (equiv.mk f H)),
end
definition is_embedding_of_is_equiv [instance] (f : A → B) [H : is_equiv f] : is_embedding f :=
is_embedding.mk _
definition is_embedding_of_is_equiv [instance] [H : is_equiv f] : is_embedding f :=
λa a', _
definition is_equiv_of_is_surjective_of_is_embedding (f : A → B)
definition is_equiv_of_is_surjective_of_is_embedding
[H : is_embedding f] [H' : is_surjective f] : is_equiv f :=
@is_equiv_of_is_contr_fun _ _ _
(λb, is_surjective_rec_on H' b
@ -146,4 +151,92 @@ namespace function
fiber_eq ((ap f)⁻¹ ((point_eq a) ⬝ (point_eq a')⁻¹))
(by rewrite (right_inv (ap f)); rewrite inv_con_cancel_right))))
definition is_split_surjective_of_is_retraction [H : is_retraction f] : is_split_surjective f :=
λb, fiber.mk (sect f b) (right_inverse f b)
definition is_constant_compose_point [constructor] [instance] (b : B)
: is_constant (f ∘ point : fiber f b → B) :=
is_constant.mk b (λv, by induction v with a p;exact p)
definition is_embedding_of_is_hprop_fiber [H : Π(b : B), is_hprop (fiber f b)] : is_embedding f :=
begin
intro a a',
fapply adjointify,
{ intro p, exact ap point (is_hprop.elim (fiber.mk a p) (fiber.mk a' idp))},
{ exact abstract begin
intro p, rewrite [-ap_compose],
apply @is_constant.eq _ _ _ (is_constant_ap (f ∘ point) (fiber.mk a p) (fiber.mk a' idp))
end end },
{ intro p, induction p, rewrite [▸*,is_hprop_elim_self]},
end
-- definition is_embedding_of_is_section_inv' [H : is_section f] {a : A} {b : B} (p : f a = b) :
-- a = retr f b :=
-- (left_inverse f a)⁻¹ ⬝ ap (retr f) p
-- definition is_embedding_of_is_section_inv [H : is_section f] {a a' : A} (p : f a = f a') :
-- a = a' :=
-- is_embedding_of_is_section_inv' f p ⬝ left_inverse f a'
-- definition is_embedding_of_is_section [constructor] [instance] [H : is_section f]
-- : is_embedding f :=
-- begin
-- intro a a',
-- fapply adjointify,
-- { exact is_embedding_of_is_section_inv f},
-- { exact abstract begin
-- assert H2 : Π {b : B} (p : f a = b), ap f (is_embedding_of_is_section_inv' f p) = p ⬝ _,
-- { }
-- -- intro p, rewrite [+ap_con,-ap_compose],
-- -- check_expr natural_square (left_inverse f),
-- -- induction H with g q, esimp,
-- end end },
-- { intro p, induction p, esimp, apply con.left_inv},
-- end
definition is_retraction_of_is_equiv [instance] [H : is_equiv f] : is_retraction f :=
is_retraction.mk f⁻¹ (right_inv f)
definition is_section_of_is_equiv [instance] [H : is_equiv f] : is_section f :=
is_section.mk f⁻¹ (left_inv f)
definition is_equiv_of_is_section_of_is_retraction [H1 : is_retraction f] [H2 : is_section f]
: is_equiv f :=
let g := sect f in let h := retr f in
adjointify f
(g)
(right_inverse f)
(λa, calc
g (f a) = h (f (g (f a))) : left_inverse
... = h (f a) : right_inverse f
... = a : left_inverse)
section
local attribute is_equiv_of_is_section_of_is_retraction [instance]
variable (f)
definition is_hprop_is_retraction_prod_is_section : is_hprop (is_retraction f × is_section f) :=
begin
apply is_hprop_of_imp_is_contr, intro H, induction H with H1 H2,
exact _,
end
end
variable {f}
local attribute is_hprop_is_retraction_prod_is_section [instance]
definition is_retraction_prod_is_section_equiv_is_equiv
: (is_retraction f × is_section f) ≃ is_equiv f :=
begin
apply equiv_of_is_hprop,
intro H, induction H, apply is_equiv_of_is_section_of_is_retraction,
intro H, split, repeat exact _
end
/-
The definitions
is_surjective_of_is_equiv
is_equiv_equiv_is_embedding_times_is_surjective
are in types.trunc
-/
end function

View file

@ -9,6 +9,26 @@ import hit.circle eq2 algebra.e_closure cubical.cube
open quotient eq circle sum sigma equiv function relation
/-
This files defines a general class of nonrecursive HITs using just quotients.
We can define any HIT X which has
- a single 0-constructor
f : A → X (for some type A)
- a single 1-constructor
e : Π{a a' : A}, R a a' → a = a' (for some (type-valued) relation R on A)
and furthermore has 2-constructors which are all of the form
p = p'
where p, p' are of the form
- refl (f a), for some a : A;
- e r, for some r : R a a';
- ap f q, where q : a = a';
- inverses of such paths;
- concatenations of such paths.
so an example 2-constructor could be (as long as it typechecks):
ap f q' ⬝ ((e r)⁻¹ ⬝ ap f q)⁻¹ ⬝ e r' = idp
-/
namespace simple_two_quotient
section
@ -73,7 +93,8 @@ namespace simple_two_quotient
ap_e_closure_elim_h e (elim_e Pj Pa Pe) t
inductive simple_two_quotient_rel : C → C → Type :=
| Rmk {} : Π{a : A} {r : T a a} (q : Q r) (x : circle), simple_two_quotient_rel (f q x) (pre_aux q)
| Rmk {} : Π{a : A} {r : T a a} (q : Q r) (x : circle),
simple_two_quotient_rel (f q x) (pre_aux q)
open simple_two_quotient_rel
definition simple_two_quotient := quotient simple_two_quotient_rel
@ -84,7 +105,7 @@ namespace simple_two_quotient
definition incl1 (s : R a a') : incl0 a = incl0 a' := ap i (e s)
definition inclt (t : T a a') : incl0 a = incl0 a' := e_closure.elim incl1 t
-- "wrong" version inclt, which is ap i (p ⬝ q) instead of ap i p ⬝ ap i q
-- it is used in the proof, because inclt is easier to work with
-- it is used in the proof, because incltw is easier to work with
protected definition incltw (t : T a a') : incl0 a = incl0 a' := ap i (et t)
protected definition inclt_eq_incltw (t : T a a') : inclt t = incltw t :=
@ -96,7 +117,7 @@ namespace simple_two_quotient
protected definition incl2w (q : Q r) : incltw r = idp :=
(ap02 i (elim_loop (j a) (et r))⁻¹) ⬝
(ap_compose i (f q) loop)⁻¹ ⬝
ap_weakly_constant (incl2' q) loop ⬝
ap_is_constant (incl2' q) loop ⬝
!con.right_inv
definition incl2 (q : Q r) : inclt r = idp :=
@ -187,11 +208,11 @@ namespace simple_two_quotient
xrewrite [eq_top_of_square
((ap_compose_natural (elim P0 P1 P2) i (elim_loop (j a) (et r)))⁻¹ʰ⁻¹ᵛ ⬝h
(ap_ap_compose (elim P0 P1 P2) i (f q) loop)⁻¹ʰ⁻¹ᵛ ⬝h
ap_ap_weakly_constant (elim P0 P1 P2) (incl2' q) loop ⬝h
ap_ap_is_constant (elim P0 P1 P2) (incl2' q) loop ⬝h
ap_con_right_inv_sq (elim P0 P1 P2) (incl2' q base)),
↑[elim_incltw]],
apply whisker_tl,
rewrite [ap_weakly_constant_eq],
rewrite [ap_is_constant_eq],
xrewrite [naturality_apdo_eq (λx, !elim_eq_of_rel) loop],
rewrite [↑elim_2,rec_loop,square_of_pathover_concato_eq,square_of_pathover_eq_concato,
eq_of_square_vconcat_eq,eq_of_square_eq_vconcat],

View file

@ -72,7 +72,7 @@ namespace is_equiv
private abbreviation adjointify_left_inv' (a : A) : g (f a) = a :=
ap g (ap f (inverse (sec a))) ⬝ ap g (ret (f a)) ⬝ sec a
private definition adjointify_adj' (a : A) : ret (f a) = ap f (adjointify_left_inv' a) :=
private theorem adjointify_adj' (a : A) : ret (f a) = ap f (adjointify_left_inv' a) :=
let fgretrfa := ap f (ap g (ret (f a))) in
let fgfinvsect := ap f (ap g (ap f (sec a)⁻¹)) in
let fgfa := f (g (f a)) in

View file

@ -9,9 +9,9 @@ Basic theorems about pathovers
prelude
import .path .equiv
open equiv is_equiv equiv.ops
open equiv is_equiv equiv.ops function
variables {A A' : Type} {B B' : A → Type} {C : Π⦃a⦄, B a → Type}
variables {A A' : Type} {B B' : A → Type} {B'' : A' → Type} {C : Π⦃a⦄, B a → Type}
{a a₂ a₃ a₄ : A} {p p' : a = a₂} {p₂ : a₂ = a₃} {p₃ : a₃ = a₄}
{b b' : B a} {b₂ b₂' : B a₂} {b₃ : B a₃} {b₄ : B a₄}
{c : C b} {c₂ : C b₂}
@ -27,16 +27,16 @@ namespace eq
/- equivalences with equality using transport -/
definition pathover_of_tr_eq [unfold 5 8] (r : p ▸ b = b₂) : b =[p] b₂ :=
by cases p; cases r; exact idpo
by cases p; cases r; constructor
definition pathover_of_eq_tr [unfold 5 8] (r : b = p⁻¹ ▸ b₂) : b =[p] b₂ :=
by cases p; cases r; exact idpo
by cases p; cases r; constructor
definition tr_eq_of_pathover [unfold 8] (r : b =[p] b₂) : p ▸ b = b₂ :=
by cases r; exact idp
by cases r; reflexivity
definition eq_tr_of_pathover [unfold 8] (r : b =[p] b₂) : b = p⁻¹ ▸ b₂ :=
by cases r; exact idp
by cases r; reflexivity
definition pathover_equiv_tr_eq [constructor] (p : a = a₂) (b : B a) (b₂ : B a₂)
: (b =[p] b₂) ≃ (p ▸ b = b₂) :=
@ -59,10 +59,10 @@ namespace eq
end
definition pathover_tr [unfold 5] (p : a = a₂) (b : B a) : b =[p] p ▸ b :=
by cases p;exact idpo
by cases p;constructor
definition tr_pathover [unfold 5] (p : a = a₂) (b : B a₂) : p⁻¹ ▸ b =[p] b :=
by cases p;exact idpo
by cases p;constructor
definition concato [unfold 12] (r : b =[p] b₂) (r₂ : b₂ =[p₂] b₃) : b =[p ⬝ p₂] b₃ :=
pathover.rec_on r₂ r
@ -73,9 +73,6 @@ namespace eq
definition apdo [unfold 6] (f : Πa, B a) (p : a = a₂) : f a =[p] f a₂ :=
eq.rec_on p idpo
definition oap [unfold 6] {C : A → Type} (f : Πa, B a → C a) (p : a = a₂) : f a =[p] f a₂ :=
eq.rec_on p idpo
definition concato_eq [unfold 10] (r : b =[p] b₂) (q : b₂ = b₂') : b =[p] b₂' :=
eq.rec_on q r
@ -115,15 +112,15 @@ namespace eq
by cases q;reflexivity
definition pathover_of_eq {a' a₂' : A'} (q : a' = a₂') : a' =[p] a₂' :=
by cases p;cases q;exact idpo
by cases p;cases q;constructor
definition pathover_constant [constructor] (p : a = a₂) (a' a₂' : A') : a' =[p] a₂' ≃ a' = a₂' :=
begin
fapply equiv.MK,
{ exact eq_of_pathover},
{ exact pathover_of_eq},
{ intro r, cases p, cases r, exact idp},
{ intro r, cases r, exact idp},
{ intro r, cases p, cases r, reflexivity},
{ intro r, cases r, reflexivity},
end
definition eq_of_pathover_idp [unfold 6] {b' : B a} (q : b =[idpath a] b') : b = b' :=
@ -166,7 +163,7 @@ namespace eq
--pathover with fibration B' ∘ f
definition pathover_ap [unfold 10] (B' : A' → Type) (f : A → A') {p : a = a₂}
{b : B' (f a)} {b₂ : B' (f a₂)} (q : b =[p] b₂) : b =[ap f p] b₂ :=
by cases q; exact idpo
by cases q; constructor
definition pathover_of_pathover_ap (B' : A' → Type) (f : A → A') {p : a = a₂}
{b : B' (f a)} {b₂ : B' (f a₂)} (q : b =[ap f p] b₂) : b =[p] b₂ :=
@ -179,15 +176,15 @@ namespace eq
{ apply pathover_ap},
{ apply pathover_of_pathover_ap},
{ intro q, cases p, esimp, apply (idp_rec_on q), apply idp},
{ intro q, cases q, exact idp},
{ intro q, cases q, reflexivity},
end
definition apdo_con (f : Πa, B a) (p : a = a₂) (q : a₂ = a₃)
: apdo f (p ⬝ q) = apdo f p ⬝o apdo f q :=
by cases p; cases q; exact idp
by cases p; cases q; reflexivity
definition apdo_inv (f : Πa, B a) (p : a = a₂) : apdo f p⁻¹ = (apdo f p)⁻¹ᵒ :=
by cases p; exact idp
by cases p; reflexivity
definition apdo_eq_pathover_of_eq_ap (f : A → A') (p : a = a₂) :
apdo f p = pathover_of_eq (ap f p) :=
@ -215,13 +212,13 @@ namespace eq
by induction q;reflexivity
variable {C}
definition apo (f : Πa, B a → B' a) {Ha : a = a₂} (Hb : b =[Ha] b₂)
: f a b =[Ha] f a₂ b₂ :=
by induction Hb; exact idpo
definition apo {f : A → A'} (g : Πa, B a → B'' (f a))
(q : b =[p] b₂) : g a b =[p] g a₂ b₂ :=
by induction q; constructor
definition apo011 (f : Πa, B a → A') (Ha : a = a₂) (Hb : b =[Ha] b₂)
: f a b = f a₂ b₂ :=
by cases Hb; exact idp
by cases Hb; reflexivity
definition apo0111 (f : Πa b, C b → A') (Ha : a = a₂) (Hb : b =[Ha] b₂)
(Hc : c =[apo011 C Ha Hb] c₂) : f a b c = f a₂ b₂ c₂ :=
@ -229,15 +226,23 @@ namespace eq
definition apo11 {f : Πb, C b} {g : Πb₂, C b₂} (r : f =[p] g)
{b : B a} {b₂ : B a₂} (q : b =[p] b₂) : f b =[apo011 C p q] g b₂ :=
by cases r; apply (idp_rec_on q); exact idpo
by cases r; apply (idp_rec_on q); constructor
definition apdo10 {f : Πb, C b} {g : Πb₂, C b₂} (r : f =[p] g)
(b : B a) : f b =[apo011 C p !pathover_tr] g (p ▸ b) :=
by cases r; exact idpo
by cases r; constructor
definition apo10 {f : B a → B' a} {g : B a₂ → B' a₂} (r : f =[p] g)
(b : B a) : f b =[p] g (p ▸ b) :=
by cases r; exact idpo
by cases r; constructor
definition apdo_compose1 (g : Πa, B a → B' a) (f : Πa, B a) (p : a = a₂)
: apdo (g ∘' f) p = apo g (apdo f p) :=
by induction p; reflexivity
definition apdo_compose2 (g : Πa', B'' a') (f : A → A') (p : a = a₂)
: apdo (λa, g (f a)) p = pathover_of_pathover_ap B'' f (apdo g (ap f p)) :=
by induction p; reflexivity
definition cono.right_inv_eq (q : b = b')
: concato_eq (pathover_idp_of_eq q) q⁻¹ = (idpo : b =[refl a] b) :=
@ -263,4 +268,33 @@ namespace eq
definition change_path_equiv' (f : Π{a}, B a ≃ B' a) (r : f b =[p] f b₂) : b =[p] b₂ :=
(left_inv f b)⁻¹ ⬝po change_path_equiv (λa, f⁻¹ᵉ) r ⬝op left_inv f b₂
definition change_path_of_pathover (s : p = p') (r : b =[p] b₂) (r' : b =[p'] b₂)
(q : r =[s] r') : change_path s r = r' :=
by induction s; eapply idp_rec_on q; reflexivity
definition pathover_of_change_path (s : p = p') (r : b =[p] b₂) (r' : b =[p'] b₂)
(q : change_path s r = r') : r =[s] r' :=
by induction s; induction q; constructor
definition pathover_pathover_path [constructor] (s : p = p') (r : b =[p] b₂) (r' : b =[p'] b₂) :
(r =[s] r') ≃ change_path s r = r' :=
begin
fapply equiv.MK,
{ apply change_path_of_pathover},
{ apply pathover_of_change_path},
{ intro q, induction s, induction q, reflexivity},
{ intro q, induction s, eapply idp_rec_on q, reflexivity},
end
definition inverseo2 [unfold 10] {r r' : b =[p] b₂} (s : r = r') : r⁻¹ᵒ = r'⁻¹ᵒ :=
by induction s; reflexivity
definition concato2 [unfold 15 16] {r r' : b =[p] b₂} {r₂ r₂' : b₂ =[p₂] b₃}
(s : r = r') (s₂ : r₂ = r₂') : r ⬝o r₂ = r' ⬝o r₂' :=
by induction s; induction s₂; reflexivity
infixl `◾o`:75 := concato2
postfix [parsing-only] `⁻²ᵒ`:(max+10) := inverseo2 --this notation is abusive, should we use it?
end eq

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@ -21,30 +21,34 @@ namespace pi
/- Functorial action -/
variables (f0 : A' → A) (f1 : B → B')
definition arrow_functor : (A → B) → (A' → B') := pi_functor f0 (λa, f1)
definition arrow_functor [unfold-full] : (A → B) → (A' → B') := pi_functor f0 (λa, f1)
/- Equivalences -/
definition is_equiv_arrow_functor
definition is_equiv_arrow_functor [constructor]
[H0 : is_equiv f0] [H1 : is_equiv f1] : is_equiv (arrow_functor f0 f1) :=
is_equiv_pi_functor f0 (λa, f1)
definition arrow_equiv_arrow_rev (f0 : A' ≃ A) (f1 : B ≃ B') : (A → B) ≃ (A' → B') :=
definition arrow_equiv_arrow_rev [constructor] (f0 : A' ≃ A) (f1 : B ≃ B')
: (A → B) ≃ (A' → B') :=
equiv.mk _ (is_equiv_arrow_functor f0 f1)
definition arrow_equiv_arrow (f0 : A ≃ A') (f1 : B ≃ B') : (A → B) ≃ (A' → B') :=
definition arrow_equiv_arrow [constructor] (f0 : A ≃ A') (f1 : B ≃ B') : (A → B) ≃ (A' → B') :=
arrow_equiv_arrow_rev (equiv.symm f0) f1
definition arrow_equiv_arrow_right (f1 : B ≃ B') : (A → B) ≃ (A → B') :=
variable (A)
definition arrow_equiv_arrow_right [constructor] (f1 : B ≃ B') : (A → B) ≃ (A → B') :=
arrow_equiv_arrow_rev equiv.refl f1
definition arrow_equiv_arrow_left_rev (f0 : A' ≃ A) : (A → B) ≃ (A' → B) :=
variables {A} (B)
definition arrow_equiv_arrow_left_rev [constructor] (f0 : A' ≃ A) : (A → B) ≃ (A' → B) :=
arrow_equiv_arrow_rev f0 equiv.refl
definition arrow_equiv_arrow_left (f0 : A ≃ A') : (A → B) ≃ (A' → B) :=
definition arrow_equiv_arrow_left [constructor] (f0 : A ≃ A') : (A → B) ≃ (A' → B) :=
arrow_equiv_arrow f0 equiv.refl
definition arrow_equiv_arrow_right' (f1 : A → (B ≃ B')) : (A → B) ≃ (A → B') :=
variables {B}
definition arrow_equiv_arrow_right' [constructor] (f1 : A → (B ≃ B')) : (A → B) ≃ (A → B') :=
pi_equiv_pi_id f1
/- Transport -/

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@ -91,7 +91,7 @@ namespace eq
theorem idp_con_idp {p : a = a} (q : p = idp) : idp_con p ⬝ q = ap (λp, idp ⬝ p) q :=
by cases q;reflexivity
definition ap_weakly_constant [unfold 8] {A B : Type} {f : A → B} {b : B} (p : Πx, f x = b)
definition ap_is_constant [unfold 8] {A B : Type} {f : A → B} {b : B} (p : Πx, f x = b)
{x y : A} (q : x = y) : ap f q = p x ⬝ (p y)⁻¹ :=
by induction q;exact !con.right_inv⁻¹

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@ -36,7 +36,7 @@ namespace is_equiv
fapply is_trunc_equiv_closed,
{apply fiber.sigma_char},
fapply is_contr_fiber_of_is_equiv,
apply (to_is_equiv (arrow_equiv_arrow_right (equiv.mk f H))),
apply (to_is_equiv (arrow_equiv_arrow_right B (equiv.mk f H))),
end
definition is_contr_right_coherence (u : Σ(g : B → A), f ∘ g ~ id)

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@ -129,7 +129,7 @@ namespace lift
definition is_embedding_lift [instance] : is_embedding lift :=
begin
apply is_embedding.mk, intro A A', fapply is_equiv.homotopy_closed,
intro A A', fapply is_equiv.homotopy_closed,
exact to_inv !lift_eq_lift_equiv,
exact _,
{ intro p, induction p,

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@ -170,7 +170,7 @@ namespace pi
/- Equivalences -/
definition is_equiv_pi_functor [instance] [H0 : is_equiv f0]
definition is_equiv_pi_functor [instance] [constructor] [H0 : is_equiv f0]
[H1 : Πa', is_equiv (f1 a')] : is_equiv (pi_functor f0 f1) :=
begin
apply (adjointify (pi_functor f0 f1) (pi_functor f0⁻¹
@ -187,15 +187,16 @@ namespace pi
end
end
definition pi_equiv_pi_of_is_equiv [H : is_equiv f0]
definition pi_equiv_pi_of_is_equiv [constructor] [H : is_equiv f0]
[H1 : Πa', is_equiv (f1 a')] : (Πa, B a) ≃ (Πa', B' a') :=
equiv.mk (pi_functor f0 f1) _
definition pi_equiv_pi (f0 : A' ≃ A) (f1 : Πa', (B (to_fun f0 a') ≃ B' a'))
definition pi_equiv_pi [constructor] (f0 : A' ≃ A) (f1 : Πa', (B (to_fun f0 a') ≃ B' a'))
: (Πa, B a) ≃ (Πa', B' a') :=
pi_equiv_pi_of_is_equiv (to_fun f0) (λa', to_fun (f1 a'))
definition pi_equiv_pi_id {P Q : A → Type} (g : Πa, P a ≃ Q a) : (Πa, P a) ≃ (Πa, Q a) :=
definition pi_equiv_pi_id [constructor] {P Q : A → Type} (g : Πa, P a ≃ Q a)
: (Πa, P a) ≃ (Πa, Q a) :=
pi_equiv_pi equiv.refl g
/- Truncatedness: any dependent product of n-types is an n-type -/

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@ -65,7 +65,7 @@ namespace is_trunc
end
definition is_embedding_to_fun (A B : Type) : is_embedding (@to_fun A B) :=
is_embedding.mk (λf f', !is_equiv_ap_to_fun)
λf f', !is_equiv_ap_to_fun
definition is_trunc_trunctype [instance] (n : trunc_index) : is_trunc n.+1 (n-Type) :=
begin
@ -241,7 +241,7 @@ end trunc open trunc
namespace function
variables {A B : Type}
definition is_surjective_of_is_equiv [instance] (f : A → B) [H : is_equiv f] : is_surjective f :=
is_surjective.mk (λb, !center)
λb, !center
definition is_equiv_equiv_is_embedding_times_is_surjective (f : A → B)
: is_equiv f ≃ (is_embedding f × is_surjective f) :=

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@ -341,12 +341,14 @@ order for the change to take effect."
("-1f" . ("⁻¹ᶠ"))
("-1g" . ("⁻¹ᵍ"))
("-1h" . ("⁻¹ʰ"))
("-1i" . ("⁻¹ⁱ"))
("-1m" . ("⁻¹ᵐ"))
("-1o" . ("⁻¹ᵒ"))
("-1r" . ("⁻¹ʳ"))
("-1p" . ("⁻¹ᵖ"))
("-1v" . ("⁻¹ᵛ"))
("-2" . ("⁻²"))
("-2o" . ("⁻²ᵒ"))
("-3" . ("⁻³"))
("qed" . (""))
("x" . ("×"))