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from_next (i : ι) : (Π i j, C.X i ⟶ D.X j) →+ (C.X_next i ⟶ D.X i)
add_monoid_hom.mk' (λ f, f (c.next i) i) $ λ f g, rfl
def
from_next
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
`f i' i` if `i'` comes after `i`, and 0 if there's no such `i'`. Hopefully there won't be much need for this, except in `d_next_eq_d_from_from_next` to see that `d_next` factors through `C.d_from i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_eq_d_from_from_next (f : Π i j, C.X i ⟶ D.X j) (i : ι) : d_next i f = C.d_from i ≫ from_next i f
rfl
lemma
d_next_eq_d_from_from_next
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next", "from_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_eq (f : Π i j, C.X i ⟶ D.X j) {i i' : ι} (w : c.rel i i') : d_next i f = C.d i i' ≫ f i' i
by { obtain rfl := c.next_eq' w, refl }
lemma
d_next_eq
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_comp_left (f : C ⟶ D) (g : Π i j, D.X i ⟶ E.X j) (i : ι) : d_next i (λ i j, f.f i ≫ g i j) = f.f i ≫ d_next i g
(f.comm_assoc _ _ _).symm
lemma
d_next_comp_left
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_comp_right (f : Π i j, C.X i ⟶ D.X j) (g : D ⟶ E) (i : ι) : d_next i (λ i j, f i j ≫ g.f j) = d_next i f ≫ g.f i
(category.assoc _ _ _).symm
lemma
d_next_comp_right
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d (j : ι) : (Π i j, C.X i ⟶ D.X j) →+ (C.X j ⟶ D.X j)
add_monoid_hom.mk' (λ f, f j (c.prev j) ≫ D.d (c.prev j) j) $ λ f g, preadditive.add_comp _ _ _ _ _ _
def
prev_d
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
The composition of `f j j' ≫ D.d j' j` if there is some `j'` coming before `j`, and `0` otherwise.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_prev (j : ι) : (Π i j, C.X i ⟶ D.X j) →+ (C.X j ⟶ D.X_prev j)
add_monoid_hom.mk' (λ f, f j (c.prev j)) $ λ f g, rfl
def
to_prev
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
`f j j'` if `j'` comes after `j`, and 0 if there's no such `j'`. Hopefully there won't be much need for this, except in `d_next_eq_d_from_from_next` to see that `d_next` factors through `C.d_from i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_eq_to_prev_d_to (f : Π i j, C.X i ⟶ D.X j) (j : ι) : prev_d j f = to_prev j f ≫ D.d_to j
rfl
lemma
prev_d_eq_to_prev_d_to
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "prev_d", "to_prev" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_eq (f : Π i j, C.X i ⟶ D.X j) {j j' : ι} (w : c.rel j' j) : prev_d j f = f j j' ≫ D.d j' j
by { obtain rfl := c.prev_eq' w, refl }
lemma
prev_d_eq
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_comp_left (f : C ⟶ D) (g : Π i j, D.X i ⟶ E.X j) (j : ι) : prev_d j (λ i j, f.f i ≫ g i j) = f.f j ≫ prev_d j g
category.assoc _ _ _
lemma
prev_d_comp_left
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_comp_right (f : Π i j, C.X i ⟶ D.X j) (g : D ⟶ E) (j : ι) : prev_d j (λ i j, f i j ≫ g.f j) = prev_d j f ≫ g.f j
by { dsimp [prev_d], simp only [category.assoc, g.comm] }
lemma
prev_d_comp_right
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_nat (C D : chain_complex V ℕ) (i : ℕ) (f : Π i j, C.X i ⟶ D.X j) : d_next i f = C.d i (i-1) ≫ f (i-1) i
begin dsimp [d_next], cases i, { simp only [shape, chain_complex.next_nat_zero, complex_shape.down_rel, nat.one_ne_zero, not_false_iff, zero_comp], }, { dsimp only [nat.succ_eq_add_one], have : (complex_shape.down ℕ).next (i + 1) = i + 1 - 1, { rw chain_complex.next_nat_succ, refl }, congr' 2,...
lemma
d_next_nat
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "chain_complex", "chain_complex.next_nat_succ", "chain_complex.next_nat_zero", "complex_shape.down", "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_nat (C D : cochain_complex V ℕ) (i : ℕ) (f : Π i j, C.X i ⟶ D.X j) : prev_d i f = f i (i-1) ≫ D.d (i-1) i
begin dsimp [prev_d], cases i, { simp only [shape, cochain_complex.prev_nat_zero, complex_shape.up_rel, nat.one_ne_zero, not_false_iff, comp_zero]}, { dsimp only [nat.succ_eq_add_one], have : (complex_shape.up ℕ).prev (i + 1) = i + 1 - 1, { rw cochain_complex.prev_nat_succ, refl }, congr' 2, }...
lemma
prev_d_nat
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "cochain_complex", "cochain_complex.prev_nat_succ", "cochain_complex.prev_nat_zero", "complex_shape.up", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy (f g : C ⟶ D)
(hom : Π i j, C.X i ⟶ D.X j) (zero' : ∀ i j, ¬ c.rel j i → hom i j = 0 . obviously) (comm : ∀ i, f.f i = d_next i hom + prev_d i hom + g.f i . obviously')
structure
homotopy
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "d_next", "obviously'", "prev_d" ]
A homotopy `h` between chain maps `f` and `g` consists of components `h i j : C.X i ⟶ D.X j` which are zero unless `c.rel j i`, satisfying the homotopy condition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_sub_zero : homotopy f g ≃ homotopy (f - g) 0
{ to_fun := λ h, { hom := λ i j, h.hom i j, zero' := λ i j w, h.zero _ _ w, comm := λ i, by simp [h.comm] }, inv_fun := λ h, { hom := λ i j, h.hom i j, zero' := λ i j w, h.zero _ _ w, comm := λ i, by simpa [sub_eq_iff_eq_add] using h.comm i }, left_inv := by tidy, right_inv := by tidy, }
def
homotopy.equiv_sub_zero
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homotopy", "inv_fun" ]
`f` is homotopic to `g` iff `f - g` is homotopic to `0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_eq (h : f = g) : homotopy f g
{ hom := 0, zero' := λ _ _ _, rfl, comm := λ _, by simp only [add_monoid_hom.map_zero, zero_add, h] }
def
homotopy.of_eq
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homotopy", "of_eq" ]
Equal chain maps are homotopic.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
refl (f : C ⟶ D) : homotopy f f
of_eq (rfl : f = f)
def
homotopy.refl
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homotopy", "of_eq" ]
Every chain map is homotopic to itself.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm {f g : C ⟶ D} (h : homotopy f g) : homotopy g f
{ hom := -h.hom, zero' := λ i j w, by rw [pi.neg_apply, pi.neg_apply, h.zero i j w, neg_zero], comm := λ i, by rw [add_monoid_hom.map_neg, add_monoid_hom.map_neg, h.comm, ← neg_add, ← add_assoc, neg_add_self, zero_add] }
def
homotopy.symm
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homotopy" ]
`f` is homotopic to `g` iff `g` is homotopic to `f`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
trans {e f g : C ⟶ D} (h : homotopy e f) (k : homotopy f g) : homotopy e g
{ hom := h.hom + k.hom, zero' := λ i j w, by rw [pi.add_apply, pi.add_apply, h.zero i j w, k.zero i j w, zero_add], comm := λ i, by { rw [add_monoid_hom.map_add, add_monoid_hom.map_add, h.comm, k.comm], abel }, }
def
homotopy.trans
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homotopy" ]
homotopy is a transitive relation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add {f₁ g₁ f₂ g₂ : C ⟶ D} (h₁ : homotopy f₁ g₁) (h₂ : homotopy f₂ g₂) : homotopy (f₁+f₂) (g₁+g₂)
{ hom := h₁.hom + h₂.hom, zero' := λ i j hij, by rw [pi.add_apply, pi.add_apply, h₁.zero' i j hij, h₂.zero' i j hij, add_zero], comm := λ i, by { simp only [homological_complex.add_f_apply, h₁.comm, h₂.comm, add_monoid_hom.map_add], abel, }, }
def
homotopy.add
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homological_complex.add_f_apply", "homotopy" ]
the sum of two homotopies is a homotopy between the sum of the respective morphisms.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_right {e f : C ⟶ D} (h : homotopy e f) (g : D ⟶ E) : homotopy (e ≫ g) (f ≫ g)
{ hom := λ i j, h.hom i j ≫ g.f j, zero' := λ i j w, by rw [h.zero i j w, zero_comp], comm := λ i, by simp only [h.comm i, d_next_comp_right, preadditive.add_comp, prev_d_comp_right, comp_f], }
def
homotopy.comp_right
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "d_next_comp_right", "homotopy", "prev_d_comp_right" ]
homotopy is closed under composition (on the right)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_left {f g : D ⟶ E} (h : homotopy f g) (e : C ⟶ D) : homotopy (e ≫ f) (e ≫ g)
{ hom := λ i j, e.f i ≫ h.hom i j, zero' := λ i j w, by rw [h.zero i j w, comp_zero], comm := λ i, by simp only [h.comm i, d_next_comp_left, preadditive.comp_add, prev_d_comp_left, comp_f], }
def
homotopy.comp_left
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "d_next_comp_left", "homotopy", "prev_d_comp_left" ]
homotopy is closed under composition (on the left)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp {C₁ C₂ C₃ : homological_complex V c} {f₁ g₁ : C₁ ⟶ C₂} {f₂ g₂ : C₂ ⟶ C₃} (h₁ : homotopy f₁ g₁) (h₂ : homotopy f₂ g₂) : homotopy (f₁ ≫ f₂) (g₁ ≫ g₂)
(h₁.comp_right _).trans (h₂.comp_left _)
def
homotopy.comp
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homological_complex", "homotopy" ]
homotopy is closed under composition
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_right_id {f : C ⟶ C} (h : homotopy f (𝟙 C)) (g : C ⟶ D) : homotopy (f ≫ g) g
(h.comp_right g).trans (of_eq $ category.id_comp _)
def
homotopy.comp_right_id
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homotopy", "of_eq" ]
a variant of `homotopy.comp_right` useful for dealing with homotopy equivalences.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_left_id {f : D ⟶ D} (h : homotopy f (𝟙 D)) (g : C ⟶ D) : homotopy (g ≫ f) g
(h.comp_left g).trans (of_eq $ category.comp_id _)
def
homotopy.comp_left_id
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homotopy", "of_eq" ]
a variant of `homotopy.comp_left` useful for dealing with homotopy equivalences.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map (hom : Π i j, C.X i ⟶ D.X j) : C ⟶ D
{ f := λ i, d_next i hom + prev_d i hom, comm' := λ i j hij, begin have eq1 : prev_d i hom ≫ D.d i j = 0, { simp only [prev_d, add_monoid_hom.mk'_apply, category.assoc, d_comp_d, comp_zero], }, have eq2 : C.d i j ≫ d_next j hom = 0, { simp only [d_next, add_monoid_hom.mk'_apply, d_comp_d_assoc...
def
homotopy.null_homotopic_map
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next", "d_next_eq", "prev_d", "prev_d_eq" ]
The null homotopic map associated to a family `hom` of morphisms `C_i ⟶ D_j`. This is the same datum as for the field `hom` in the structure `homotopy`. For this definition, we do not need the field `zero` of that structure as this definition uses only the maps `C_i ⟶ C_j` when `c.rel j i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map' (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : C ⟶ D
null_homotopic_map (λ i j, dite (c.rel j i) (h i j) (λ _, 0))
def
homotopy.null_homotopic_map'
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
Variant of `null_homotopic_map` where the input consists only of the relevant maps `C_i ⟶ D_j` such that `c.rel j i`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map_comp (hom : Π i j, C.X i ⟶ D.X j) (g : D ⟶ E) : null_homotopic_map hom ≫ g = null_homotopic_map (λ i j, hom i j ≫ g.f j)
begin ext n, dsimp [null_homotopic_map, from_next, to_prev, add_monoid_hom.mk'_apply], simp only [preadditive.add_comp, category.assoc, g.comm], end
lemma
homotopy.null_homotopic_map_comp
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "from_next", "to_prev" ]
Compatibility of `null_homotopic_map` with the postcomposition by a morphism of complexes.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map'_comp (hom : Π i j, c.rel j i → (C.X i ⟶ D.X j)) (g : D ⟶ E) : null_homotopic_map' hom ≫ g = null_homotopic_map' (λ i j hij, hom i j hij ≫ g.f j)
begin ext n, erw null_homotopic_map_comp, congr', ext i j, split_ifs, { refl, }, { rw zero_comp, }, end
lemma
homotopy.null_homotopic_map'_comp
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
Compatibility of `null_homotopic_map'` with the postcomposition by a morphism of complexes.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_null_homotopic_map (f : C ⟶ D) (hom : Π i j, D.X i ⟶ E.X j) : f ≫ null_homotopic_map hom = null_homotopic_map (λ i j, f.f i ≫ hom i j)
begin ext n, dsimp [null_homotopic_map, from_next, to_prev, add_monoid_hom.mk'_apply], simp only [preadditive.comp_add, category.assoc, f.comm_assoc], end
lemma
homotopy.comp_null_homotopic_map
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "from_next", "to_prev" ]
Compatibility of `null_homotopic_map` with the precomposition by a morphism of complexes.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_null_homotopic_map' (f : C ⟶ D) (hom : Π i j, c.rel j i → (D.X i ⟶ E.X j)) : f ≫ null_homotopic_map' hom = null_homotopic_map' (λ i j hij, f.f i ≫ hom i j hij)
begin ext n, erw comp_null_homotopic_map, congr', ext i j, split_ifs, { refl, }, { rw comp_zero, }, end
lemma
homotopy.comp_null_homotopic_map'
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
Compatibility of `null_homotopic_map'` with the precomposition by a morphism of complexes.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_null_homotopic_map {W : Type*} [category W] [preadditive W] (G : V ⥤ W) [G.additive] (hom : Π i j, C.X i ⟶ D.X j) : (G.map_homological_complex c).map (null_homotopic_map hom) = null_homotopic_map (λ i j, G.map (hom i j))
begin ext i, dsimp [null_homotopic_map, d_next, prev_d], simp only [G.map_comp, functor.map_add], end
lemma
homotopy.map_null_homotopic_map
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next", "prev_d" ]
Compatibility of `null_homotopic_map` with the application of additive functors
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_null_homotopic_map' {W : Type*} [category W] [preadditive W] (G : V ⥤ W) [G.additive] (hom : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : (G.map_homological_complex c).map (null_homotopic_map' hom) = null_homotopic_map' (λ i j hij, G.map (hom i j hij))
begin ext n, erw map_null_homotopic_map, congr', ext i j, split_ifs, { refl, }, { rw G.map_zero, } end
lemma
homotopy.map_null_homotopic_map'
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
Compatibility of `null_homotopic_map'` with the application of additive functors
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopy (hom : Π i j, C.X i ⟶ D.X j) (zero' : ∀ i j, ¬ c.rel j i → hom i j = 0) : homotopy (null_homotopic_map hom) 0
{ hom := hom, zero' := zero', comm := by { intro i, rw [homological_complex.zero_f_apply, add_zero], refl, }, }
def
homotopy.null_homotopy
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "homological_complex.zero_f_apply", "homotopy" ]
Tautological construction of the `homotopy` to zero for maps constructed by `null_homotopic_map`, at least when we have the `zero'` condition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopy' (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : homotopy (null_homotopic_map' h) 0
begin apply null_homotopy (λ i j, dite (c.rel j i) (h i j) (λ _, 0)), intros i j hij, dsimp, rw [dite_eq_right_iff], intro hij', exfalso, exact hij hij', end
def
homotopy.null_homotopy'
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "dite_eq_right_iff", "homotopy" ]
Homotopy to zero for maps constructed with `null_homotopic_map'`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map_f {k₂ k₁ k₀ : ι} (r₂₁ : c.rel k₂ k₁) (r₁₀ : c.rel k₁ k₀) (hom : Π i j, C.X i ⟶ D.X j) : (null_homotopic_map hom).f k₁ = C.d k₁ k₀ ≫ hom k₀ k₁ + hom k₁ k₂ ≫ D.d k₂ k₁
by { dsimp only [null_homotopic_map], rw [d_next_eq hom r₁₀, prev_d_eq hom r₂₁], }
lemma
homotopy.null_homotopic_map_f
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next_eq", "prev_d_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map'_f {k₂ k₁ k₀ : ι} (r₂₁ : c.rel k₂ k₁) (r₁₀ : c.rel k₁ k₀) (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : (null_homotopic_map' h).f k₁ = C.d k₁ k₀ ≫ h k₀ k₁ r₁₀ + h k₁ k₂ r₂₁ ≫ D.d k₂ k₁
begin simp only [← null_homotopic_map'], rw null_homotopic_map_f r₂₁ r₁₀ (λ i j, dite (c.rel j i) (h i j) (λ _, 0)), dsimp, split_ifs, refl, end
lemma
homotopy.null_homotopic_map'_f
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map_f_of_not_rel_left {k₁ k₀ : ι} (r₁₀ : c.rel k₁ k₀) (hk₀ : ∀ l : ι, ¬c.rel k₀ l) (hom : Π i j, C.X i ⟶ D.X j) : (null_homotopic_map hom).f k₀ = hom k₀ k₁ ≫ D.d k₁ k₀
begin dsimp only [null_homotopic_map], rw [prev_d_eq hom r₁₀, d_next, add_monoid_hom.mk'_apply, C.shape, zero_comp, zero_add], exact hk₀ _ end
lemma
homotopy.null_homotopic_map_f_of_not_rel_left
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next", "prev_d_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map'_f_of_not_rel_left {k₁ k₀ : ι} (r₁₀ : c.rel k₁ k₀) (hk₀ : ∀ l : ι, ¬c.rel k₀ l) (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : (null_homotopic_map' h).f k₀ = h k₀ k₁ r₁₀ ≫ D.d k₁ k₀
begin simp only [← null_homotopic_map'], rw null_homotopic_map_f_of_not_rel_left r₁₀ hk₀ (λ i j, dite (c.rel j i) (h i j) (λ _, 0)), dsimp, split_ifs, refl, end
lemma
homotopy.null_homotopic_map'_f_of_not_rel_left
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map_f_of_not_rel_right {k₁ k₀ : ι} (r₁₀ : c.rel k₁ k₀) (hk₁ : ∀ l : ι, ¬c.rel l k₁) (hom : Π i j, C.X i ⟶ D.X j) : (null_homotopic_map hom).f k₁ = C.d k₁ k₀ ≫ hom k₀ k₁
begin dsimp only [null_homotopic_map], rw [d_next_eq hom r₁₀, prev_d, add_monoid_hom.mk'_apply, D.shape, comp_zero, add_zero], exact hk₁ _, end
lemma
homotopy.null_homotopic_map_f_of_not_rel_right
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next_eq", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map'_f_of_not_rel_right {k₁ k₀ : ι} (r₁₀ : c.rel k₁ k₀) (hk₁ : ∀ l : ι, ¬c.rel l k₁) (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : (null_homotopic_map' h).f k₁ = C.d k₁ k₀ ≫ h k₀ k₁ r₁₀
begin simp only [← null_homotopic_map'], rw null_homotopic_map_f_of_not_rel_right r₁₀ hk₁ (λ i j, dite (c.rel j i) (h i j) (λ _, 0)), dsimp, split_ifs, refl, end
lemma
homotopy.null_homotopic_map'_f_of_not_rel_right
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map_f_eq_zero {k₀ : ι} (hk₀ : ∀ l : ι, ¬c.rel k₀ l) (hk₀' : ∀ l : ι, ¬c.rel l k₀) (hom : Π i j, C.X i ⟶ D.X j) : (null_homotopic_map hom).f k₀ = 0
begin dsimp [null_homotopic_map, d_next, prev_d], rw [C.shape, D.shape, zero_comp, comp_zero, add_zero]; apply_assumption, end
lemma
homotopy.null_homotopic_map_f_eq_zero
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "d_next", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
null_homotopic_map'_f_eq_zero {k₀ : ι} (hk₀ : ∀ l : ι, ¬c.rel k₀ l) (hk₀' : ∀ l : ι, ¬c.rel l k₀) (h : Π i j, c.rel j i → (C.X i ⟶ D.X j)) : (null_homotopic_map' h).f k₀ = 0
begin simp only [← null_homotopic_map'], exact null_homotopic_map_f_eq_zero hk₀ hk₀' (λ i j, dite (c.rel j i) (h i j) (λ _, 0)), end
lemma
homotopy.null_homotopic_map'_f_eq_zero
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_chain_complex (f : Π i j, P.X i ⟶ Q.X j) (j : ℕ) : prev_d j f = f j (j+1) ≫ Q.d _ _
begin dsimp [prev_d], have : (complex_shape.down ℕ).prev j = j + 1 := chain_complex.prev ℕ j, congr' 2, end
lemma
homotopy.prev_d_chain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "chain_complex.prev", "complex_shape.down", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_succ_chain_complex (f : Π i j, P.X i ⟶ Q.X j) (i : ℕ) : d_next (i+1) f = P.d _ _ ≫ f i (i+1)
begin dsimp [d_next], have : (complex_shape.down ℕ).next (i + 1) = i := chain_complex.next_nat_succ _, congr' 2, end
lemma
homotopy.d_next_succ_chain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "chain_complex.next_nat_succ", "complex_shape.down", "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_zero_chain_complex (f : Π i j, P.X i ⟶ Q.X j) : d_next 0 f = 0
begin dsimp [d_next], rw [P.shape, zero_comp], rw chain_complex.next_nat_zero, dsimp, dec_trivial, end
lemma
homotopy.d_next_zero_chain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "chain_complex.next_nat_zero", "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_inductive_aux₁ : Π n, Σ' (f : P.X n ⟶ Q.X (n+1)) (f' : P.X (n+1) ⟶ Q.X (n+2)), e.f (n+1) = P.d (n+1) n ≫ f + f' ≫ Q.d (n+2) (n+1)
| 0 := ⟨zero, one, comm_one⟩ | 1 := ⟨one, (succ 0 ⟨zero, one, comm_one⟩).1, (succ 0 ⟨zero, one, comm_one⟩).2⟩ | (n+2) := ⟨(mk_inductive_aux₁ (n+1)).2.1, (succ (n+1) (mk_inductive_aux₁ (n+1))).1, (succ (n+1) (mk_inductive_aux₁ (n+1))).2⟩
def
homotopy.mk_inductive_aux₁
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
An auxiliary construction for `mk_inductive`. Here we build by induction a family of diagrams, but don't require at the type level that these successive diagrams actually agree. They do in fact agree, and we then capture that at the type level (i.e. by constructing a homotopy) in `mk_inductive`. At this stage, we don...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_inductive_aux₂ : Π n, Σ' (f : P.X_next n ⟶ Q.X n) (f' : P.X n ⟶ Q.X_prev n), e.f n = P.d_from n ≫ f + f' ≫ Q.d_to n
| 0 := ⟨0, zero ≫ (Q.X_prev_iso rfl).inv, by simpa using comm_zero⟩ | (n+1) := let I := mk_inductive_aux₁ e zero comm_zero one comm_one succ n in ⟨(P.X_next_iso rfl).hom ≫ I.1, I.2.1 ≫ (Q.X_prev_iso rfl).inv, by simpa using I.2.2⟩
def
homotopy.mk_inductive_aux₂
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
An auxiliary construction for `mk_inductive`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_inductive_aux₃ (i j : ℕ) (h : i+1 = j) : (mk_inductive_aux₂ e zero comm_zero one comm_one succ i).2.1 ≫ (Q.X_prev_iso h).hom = (P.X_next_iso h).inv ≫ (mk_inductive_aux₂ e zero comm_zero one comm_one succ j).1
by subst j; rcases i with (_|_|i); { dsimp, simp, }
lemma
homotopy.mk_inductive_aux₃
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_inductive : homotopy e 0
{ hom := λ i j, if h : i + 1 = j then (mk_inductive_aux₂ e zero comm_zero one comm_one succ i).2.1 ≫ (Q.X_prev_iso h).hom else 0, zero' := λ i j w, by rwa dif_neg, comm := λ i, begin dsimp, simp only [add_zero], convert (mk_inductive_aux₂ e zero comm_zero one comm_one succ i).2.2, { cases i, ...
def
homotopy.mk_inductive
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "aux", "chain_complex.next_nat_succ", "chain_complex.next_nat_zero", "chain_complex.prev", "comm", "complex_shape.down", "from_next", "homotopy", "to_prev" ]
A constructor for a `homotopy e 0`, for `e` a chain map between `ℕ`-indexed chain complexes, working by induction. You need to provide the components of the homotopy in degrees 0 and 1, show that these satisfy the homotopy condition, and then give a construction of each component, and the fact that it satisfies the ho...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
d_next_cochain_complex (f : Π i j, P.X i ⟶ Q.X j) (j : ℕ) : d_next j f = P.d _ _ ≫ f (j+1) j
begin dsimp [d_next], have : (complex_shape.up ℕ).next j = j + 1 := cochain_complex.next ℕ j, congr' 2, end
lemma
homotopy.d_next_cochain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "cochain_complex.next", "complex_shape.up", "d_next" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_succ_cochain_complex (f : Π i j, P.X i ⟶ Q.X j) (i : ℕ) : prev_d (i+1) f = f (i+1) _ ≫ Q.d i (i+1)
begin dsimp [prev_d], have : (complex_shape.up ℕ).prev (i+1) = i := cochain_complex.prev_nat_succ i, congr' 2, end
lemma
homotopy.prev_d_succ_cochain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "cochain_complex.prev_nat_succ", "complex_shape.up", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prev_d_zero_cochain_complex (f : Π i j, P.X i ⟶ Q.X j) : prev_d 0 f = 0
begin dsimp [prev_d], rw [Q.shape, comp_zero], rw [cochain_complex.prev_nat_zero], dsimp, dec_trivial, end
lemma
homotopy.prev_d_zero_cochain_complex
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "cochain_complex.prev_nat_zero", "prev_d" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_coinductive_aux₁ : Π n, Σ' (f : P.X (n+1) ⟶ Q.X n) (f' : P.X (n+2) ⟶ Q.X (n+1)), e.f (n+1) = f ≫ Q.d n (n+1) + P.d (n+1) (n+2) ≫ f'
| 0 := ⟨zero, one, comm_one⟩ | 1 := ⟨one, (succ 0 ⟨zero, one, comm_one⟩).1, (succ 0 ⟨zero, one, comm_one⟩).2⟩ | (n+2) := ⟨(mk_coinductive_aux₁ (n+1)).2.1, (succ (n+1) (mk_coinductive_aux₁ (n+1))).1, (succ (n+1) (mk_coinductive_aux₁ (n+1))).2⟩
def
homotopy.mk_coinductive_aux₁
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
An auxiliary construction for `mk_coinductive`. Here we build by induction a family of diagrams, but don't require at the type level that these successive diagrams actually agree. They do in fact agree, and we then capture that at the type level (i.e. by constructing a homotopy) in `mk_coinductive`. At this stage, we...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_coinductive_aux₂ : Π n, Σ' (f : P.X n ⟶ Q.X_prev n) (f' : P.X_next n ⟶ Q.X n), e.f n = f ≫ Q.d_to n + P.d_from n ≫ f'
| 0 := ⟨0, (P.X_next_iso rfl).hom ≫ zero, by simpa using comm_zero⟩ | (n+1) := let I := mk_coinductive_aux₁ e zero comm_zero one comm_one succ n in ⟨I.1 ≫ (Q.X_prev_iso rfl).inv, (P.X_next_iso rfl).hom ≫ I.2.1, by simpa using I.2.2⟩
def
homotopy.mk_coinductive_aux₂
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
An auxiliary construction for `mk_inductive`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_coinductive_aux₃ (i j : ℕ) (h : i + 1 = j) : (P.X_next_iso h).inv ≫ (mk_coinductive_aux₂ e zero comm_zero one comm_one succ i).2.1 = (mk_coinductive_aux₂ e zero comm_zero one comm_one succ j).1 ≫ (Q.X_prev_iso h).hom
by subst j; rcases i with (_|_|i); { dsimp, simp, }
lemma
homotopy.mk_coinductive_aux₃
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_coinductive : homotopy e 0
{ hom := λ i j, if h : j + 1 = i then (P.X_next_iso h).inv ≫ (mk_coinductive_aux₂ e zero comm_zero one comm_one succ j).2.1 else 0, zero' := λ i j w, by rwa dif_neg, comm := λ i, begin dsimp, rw [add_zero, add_comm], convert (mk_coinductive_aux₂ e zero comm_zero one comm_one succ i).2.2 using ...
def
homotopy.mk_coinductive
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "aux", "cochain_complex.next", "cochain_complex.prev_nat_succ", "cochain_complex.prev_nat_zero", "comm", "complex_shape.up", "from_next", "homotopy", "to_prev" ]
A constructor for a `homotopy e 0`, for `e` a chain map between `ℕ`-indexed cochain complexes, working by induction. You need to provide the components of the homotopy in degrees 0 and 1, show that these satisfy the homotopy condition, and then give a construction of each component, and the fact that it satisfies the ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_equiv (C D : homological_complex V c)
(hom : C ⟶ D) (inv : D ⟶ C) (homotopy_hom_inv_id : homotopy (hom ≫ inv) (𝟙 C)) (homotopy_inv_hom_id : homotopy (inv ≫ hom) (𝟙 D))
structure
homotopy_equiv
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homological_complex", "homotopy" ]
A homotopy equivalence between two chain complexes consists of a chain map each way, and homotopies from the compositions to the identity chain maps. Note that this contains data; arguably it might be more useful for many applications if we truncated it to a Prop.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
refl (C : homological_complex V c) : homotopy_equiv C C
{ hom := 𝟙 C, inv := 𝟙 C, homotopy_hom_inv_id := by simp, homotopy_inv_hom_id := by simp, }
def
homotopy_equiv.refl
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homological_complex", "homotopy_equiv" ]
Any complex is homotopy equivalent to itself.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm {C D : homological_complex V c} (f : homotopy_equiv C D) : homotopy_equiv D C
{ hom := f.inv, inv := f.hom, homotopy_hom_inv_id := f.homotopy_inv_hom_id, homotopy_inv_hom_id := f.homotopy_hom_inv_id, }
def
homotopy_equiv.symm
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homological_complex", "homotopy_equiv" ]
Being homotopy equivalent is a symmetric relation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
trans {C D E : homological_complex V c} (f : homotopy_equiv C D) (g : homotopy_equiv D E) : homotopy_equiv C E
{ hom := f.hom ≫ g.hom, inv := g.inv ≫ f.inv, homotopy_hom_inv_id := by simpa using ((g.homotopy_hom_inv_id.comp_right_id f.inv).comp_left f.hom).trans f.homotopy_hom_inv_id, homotopy_inv_hom_id := by simpa using ((f.homotopy_inv_hom_id.comp_right_id g.hom).comp_left g.inv).trans g.homotopy_inv_hom_id, }
def
homotopy_equiv.trans
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homological_complex", "homotopy_equiv" ]
Homotopy equivalence is a transitive relation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_iso {ι : Type*} {V : Type u} [category.{v} V] [preadditive V] {c : complex_shape ι} {C D : homological_complex V c} (f : C ≅ D) : homotopy_equiv C D
⟨f.hom, f.inv, homotopy.of_eq f.3, homotopy.of_eq f.4⟩
def
homotopy_equiv.of_iso
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "complex_shape", "homological_complex", "homotopy.of_eq", "homotopy_equiv" ]
An isomorphism of complexes induces a homotopy equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_map_eq_of_homotopy (h : homotopy f g) (i : ι) : (homology_functor V c i).map f = (homology_functor V c i).map g
begin dsimp [homology_functor], apply eq_of_sub_eq_zero, ext, simp only [homology.π_map, comp_zero, preadditive.comp_sub], dsimp [kernel_subobject_map], simp_rw [h.comm i], simp only [zero_add, zero_comp, d_next_eq_d_from_from_next, kernel_subobject_arrow_comp_assoc, preadditive.comp_add], rw [←prea...
theorem
homology_map_eq_of_homotopy
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "category_theory.subobject.factor_thru_add_sub_factor_thru_right", "d_next_eq_d_from_from_next", "homology.π_map", "homology_functor", "homotopy", "prev_d_eq_to_prev_d_to" ]
Homotopic maps induce the same map on homology.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_obj_iso_of_homotopy_equiv (f : homotopy_equiv C D) (i : ι) : (homology_functor V c i).obj C ≅ (homology_functor V c i).obj D
{ hom := (homology_functor V c i).map f.hom, inv := (homology_functor V c i).map f.inv, hom_inv_id' := begin rw [←functor.map_comp, homology_map_eq_of_homotopy f.homotopy_hom_inv_id, category_theory.functor.map_id], end, inv_hom_id' := begin rw [←functor.map_comp, homology_map_eq_of_homotopy f.hom...
def
homology_obj_iso_of_homotopy_equiv
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homology_functor", "homology_map_eq_of_homotopy", "homotopy_equiv" ]
Homotopy equivalent complexes have isomorphic homologies.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor.map_homotopy (F : V ⥤ W) [F.additive] {f g : C ⟶ D} (h : homotopy f g) : homotopy ((F.map_homological_complex c).map f) ((F.map_homological_complex c).map g)
{ hom := λ i j, F.map (h.hom i j), zero' := λ i j w, by { rw [h.zero i j w, F.map_zero], }, comm := λ i, begin dsimp [d_next, prev_d] at *, rw h.comm i, simp only [F.map_add, ← F.map_comp], refl end, }
def
category_theory.functor.map_homotopy
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "comm", "d_next", "homotopy", "prev_d" ]
An additive functor takes homotopies to homotopies.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor.map_homotopy_equiv (F : V ⥤ W) [F.additive] (h : homotopy_equiv C D) : homotopy_equiv ((F.map_homological_complex c).obj C) ((F.map_homological_complex c).obj D)
{ hom := (F.map_homological_complex c).map h.hom, inv := (F.map_homological_complex c).map h.inv, homotopy_hom_inv_id := begin rw [←(F.map_homological_complex c).map_comp, ←(F.map_homological_complex c).map_id], exact F.map_homotopy h.homotopy_hom_inv_id, end, homotopy_inv_hom_id := begin rw [←(F.ma...
def
category_theory.functor.map_homotopy_equiv
algebra.homology
src/algebra/homology/homotopy.lean
[ "algebra.homology.additive", "tactic.abel" ]
[ "homotopy_equiv", "map_comp", "map_id" ]
An additive functor preserves homotopy equivalences.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopic : hom_rel (homological_complex V c)
λ C D f g, nonempty (homotopy f g)
def
homotopic
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "hom_rel", "homological_complex", "homotopy" ]
The congruence on `homological_complex V c` given by the existence of a homotopy.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_congruence : congruence (homotopic V c)
{ is_equiv := λ C D, { refl := λ C, ⟨homotopy.refl C⟩, symm := λ f g ⟨w⟩, ⟨w.symm⟩, trans := λ f g h ⟨w₁⟩ ⟨w₂⟩, ⟨w₁.trans w₂⟩, }, comp_left := λ E F G m₁ m₂ g ⟨i⟩, ⟨i.comp_left _⟩, comp_right := λ E F G f m₁ m₂ ⟨i⟩, ⟨i.comp_right _⟩, }
instance
homotopy_congruence
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homotopic" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_category
category_theory.quotient (homotopic V c)
def
homotopy_category
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient", "homotopic" ]
`homotopy_category V c` is the category of chain complexes of shape `c` in `V`, with chain maps identified when they are homotopic.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient : homological_complex V c ⥤ homotopy_category V c
category_theory.quotient.functor _
def
homotopy_category.quotient
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient.functor", "homological_complex", "homotopy_category" ]
The quotient functor from complexes to the homotopy category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_obj_as (C : homological_complex V c) : ((quotient V c).obj C).as = C
rfl
lemma
homotopy_category.quotient_obj_as
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_map_out {C D : homotopy_category V c} (f : C ⟶ D) : (quotient V c).map f.out = f
quot.out_eq _
lemma
homotopy_category.quotient_map_out
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homotopy_category", "quot.out_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_homotopy {C D : homological_complex V c} (f g : C ⟶ D) (h : homotopy f g) : (quotient V c).map f = (quotient V c).map g
category_theory.quotient.sound _ ⟨h⟩
lemma
homotopy_category.eq_of_homotopy
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient.sound", "homological_complex", "homotopy" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_of_eq {C D : homological_complex V c} (f g : C ⟶ D) (w : (quotient V c).map f = (quotient V c).map g) : homotopy f g
((quotient.functor_map_eq_iff _ _ _).mp w).some
def
homotopy_category.homotopy_of_eq
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex", "homotopy" ]
If two chain maps become equal in the homotopy category, then they are homotopic.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_out_map {C D : homological_complex V c} (f : C ⟶ D) : homotopy ((quotient V c).map f).out f
begin apply homotopy_of_eq, simp, end
def
homotopy_category.homotopy_out_map
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex", "homotopy" ]
An arbitrarily chosen representation of the image of a chain map in the homotopy category is homotopic to the original chain map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_map_out_comp_out {C D E : homotopy_category V c} (f : C ⟶ D) (g : D ⟶ E) : (quotient V c).map (quot.out f ≫ quot.out g) = f ≫ g
by conv_rhs { erw [←quotient_map_out f, ←quotient_map_out g, ←(quotient V c).map_comp], }
lemma
homotopy_category.quotient_map_out_comp_out
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homotopy_category", "map_comp", "quot.out" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iso_of_homotopy_equiv {C D : homological_complex V c} (f : homotopy_equiv C D) : (quotient V c).obj C ≅ (quotient V c).obj D
{ hom := (quotient V c).map f.hom, inv := (quotient V c).map f.inv, hom_inv_id' := begin rw [←(quotient V c).map_comp, ←(quotient V c).map_id], exact eq_of_homotopy _ _ f.homotopy_hom_inv_id, end, inv_hom_id' := begin rw [←(quotient V c).map_comp, ←(quotient V c).map_id], exact eq_of_homotopy _ ...
def
homotopy_category.iso_of_homotopy_equiv
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex", "homotopy_equiv", "map_comp", "map_id" ]
Homotopy equivalent complexes become isomorphic in the homotopy category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopy_equiv_of_iso {C D : homological_complex V c} (i : (quotient V c).obj C ≅ (quotient V c).obj D) : homotopy_equiv C D
{ hom := quot.out i.hom, inv := quot.out i.inv, homotopy_hom_inv_id := homotopy_of_eq _ _ (by { simp, refl, }), homotopy_inv_hom_id := homotopy_of_eq _ _ (by { simp, refl, }), }
def
homotopy_category.homotopy_equiv_of_iso
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex", "homotopy_equiv", "quot.out" ]
If two complexes become isomorphic in the homotopy category, then they were homotopy equivalent.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_functor (i : ι) : homotopy_category V c ⥤ V
category_theory.quotient.lift _ (homology_functor V c i) (λ C D f g ⟨h⟩, homology_map_eq_of_homotopy h i)
def
homotopy_category.homology_functor
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient.lift", "homology_functor", "homology_map_eq_of_homotopy", "homotopy_category" ]
The `i`-th homology, as a functor from the homotopy category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_factors (i : ι) : quotient V c ⋙ homology_functor V c i ≅ _root_.homology_functor V c i
category_theory.quotient.lift.is_lift _ _ _
def
homotopy_category.homology_factors
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient.lift.is_lift", "homology_functor" ]
The homology functor on the homotopy category is just the usual homology functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_factors_hom_app (i : ι) (C : homological_complex V c) : (homology_factors V c i).hom.app C = 𝟙 _
rfl
lemma
homotopy_category.homology_factors_hom_app
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_factors_inv_app (i : ι) (C : homological_complex V c) : (homology_factors V c i).inv.app C = 𝟙 _
rfl
lemma
homotopy_category.homology_factors_inv_app
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "homological_complex" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homology_functor_map_factors (i : ι) {C D : homological_complex V c} (f : C ⟶ D) : (_root_.homology_functor V c i).map f = ((homology_functor V c i).map ((quotient V c).map f) : _)
(category_theory.quotient.lift_map_functor_map _ (_root_.homology_functor V c i) _ f).symm
lemma
homotopy_category.homology_functor_map_factors
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "category_theory.quotient.lift_map_functor_map", "homological_complex", "homology_functor" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
functor.map_homotopy_category (c : complex_shape ι) (F : V ⥤ W) [F.additive] : homotopy_category V c ⥤ homotopy_category W c
{ obj := λ C, (homotopy_category.quotient W c).obj ((F.map_homological_complex c).obj C.as), map := λ C D f, (homotopy_category.quotient W c).map ((F.map_homological_complex c).map (quot.out f)), map_id' := λ C, begin rw ←(homotopy_category.quotient W c).map_id, apply homotopy_category.eq_of_homotopy, ...
def
category_theory.functor.map_homotopy_category
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "complex_shape", "homotopy_category", "homotopy_category.eq_of_homotopy", "homotopy_category.homotopy_of_eq", "homotopy_category.quotient", "homotopy_category.quotient_map_out_comp_out", "map_comp", "map_id", "quot.out", "quot.out_eq" ]
An additive functor induces a functor between homotopy categories.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_trans.map_homotopy_category {F G : V ⥤ W} [F.additive] [G.additive] (α : F ⟶ G) (c : complex_shape ι) : F.map_homotopy_category c ⟶ G.map_homotopy_category c
{ app := λ C, (homotopy_category.quotient W c).map ((nat_trans.map_homological_complex α c).app C.as), naturality' := λ C D f, begin dsimp, simp only [←functor.map_comp], congr' 1, ext, dsimp, simp, end }
def
category_theory.nat_trans.map_homotopy_category
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "complex_shape", "homotopy_category.quotient" ]
A natural transformation induces a natural transformation between the induced functors on the homotopy category.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_trans.map_homotopy_category_id (c : complex_shape ι) (F : V ⥤ W) [F.additive] : nat_trans.map_homotopy_category (𝟙 F) c = 𝟙 (F.map_homotopy_category c)
by tidy
lemma
category_theory.nat_trans.map_homotopy_category_id
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "complex_shape" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_trans.map_homotopy_category_comp (c : complex_shape ι) {F G H : V ⥤ W} [F.additive] [G.additive] [H.additive] (α : F ⟶ G) (β : G ⟶ H): nat_trans.map_homotopy_category (α ≫ β) c = nat_trans.map_homotopy_category α c ≫ nat_trans.map_homotopy_category β c
by tidy
lemma
category_theory.nat_trans.map_homotopy_category_comp
algebra.homology
src/algebra/homology/homotopy_category.lean
[ "algebra.homology.homotopy", "category_theory.quotient" ]
[ "complex_shape" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_le_kernel (w : f ≫ g = 0) : image_subobject f ≤ kernel_subobject g
image_subobject_le_mk _ _ (kernel.lift _ _ w) (by simp)
lemma
image_le_kernel
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel (w : f ≫ g = 0) : (image_subobject f : V) ⟶ (kernel_subobject g : V)
(subobject.of_le _ _ (image_le_kernel _ _ w))
def
image_to_kernel
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_le_kernel" ]
The canonical morphism `image_subobject f ⟶ kernel_subobject g` when `f ≫ g = 0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subobject_of_le_as_image_to_kernel (w : f ≫ g = 0) (h) : subobject.of_le (image_subobject f) (kernel_subobject g) h = image_to_kernel f g w
rfl
lemma
subobject_of_le_as_image_to_kernel
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
Prefer `image_to_kernel`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_arrow (w : f ≫ g = 0) : image_to_kernel f g w ≫ (kernel_subobject g).arrow = (image_subobject f).arrow
by simp [image_to_kernel]
lemma
image_to_kernel_arrow
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
factor_thru_image_subobject_comp_image_to_kernel (w : f ≫ g = 0) : factor_thru_image_subobject f ≫ image_to_kernel f g w = factor_thru_kernel_subobject g f w
by { ext, simp, }
lemma
factor_thru_image_subobject_comp_image_to_kernel
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_zero_left [has_kernels V] [has_zero_object V] {w} : image_to_kernel (0 : A ⟶ B) g w = 0
by { ext, simp, }
lemma
image_to_kernel_zero_left
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_zero_right [has_images V] {w} : image_to_kernel f (0 : B ⟶ C) w = (image_subobject f).arrow ≫ inv (kernel_subobject (0 : B ⟶ C)).arrow
by { ext, simp }
lemma
image_to_kernel_zero_right
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_comp_right {D : V} (h : C ⟶ D) (w : f ≫ g = 0) : image_to_kernel f (g ≫ h) (by simp [reassoc_of w]) = image_to_kernel f g w ≫ subobject.of_le _ _ (kernel_subobject_comp_le g h)
by { ext, simp }
lemma
image_to_kernel_comp_right
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_comp_left {Z : V} (h : Z ⟶ A) (w : f ≫ g = 0) : image_to_kernel (h ≫ f) g (by simp [w]) = subobject.of_le _ _ (image_subobject_comp_le h f) ≫ image_to_kernel f g w
by { ext, simp }
lemma
image_to_kernel_comp_left
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_comp_mono {D : V} (h : C ⟶ D) [mono h] (w) : image_to_kernel f (g ≫ h) w = image_to_kernel f g ((cancel_mono h).mp (by simpa using w : (f ≫ g) ≫ h = 0 ≫ h)) ≫ (subobject.iso_of_eq _ _ (kernel_subobject_comp_mono g h)).inv
by { ext, simp, }
lemma
image_to_kernel_comp_mono
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_epi_comp {Z : V} (h : Z ⟶ A) [epi h] (w) : image_to_kernel (h ≫ f) g w = subobject.of_le _ _ (image_subobject_comp_le h f) ≫ image_to_kernel f g ((cancel_epi h).mp (by simpa using w : h ≫ f ≫ g = h ≫ 0))
by { ext, simp, }
lemma
image_to_kernel_epi_comp
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_comp_hom_inv_comp [has_equalizers V] [has_images V] {Z : V} {i : B ≅ Z} (w) : image_to_kernel (f ≫ i.hom) (i.inv ≫ g) w = (image_subobject_comp_iso _ _).hom ≫ image_to_kernel f g (by simpa using w) ≫ (kernel_subobject_iso_comp i.inv g).inv
by { ext, simp, }
lemma
image_to_kernel_comp_hom_inv_comp
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_to_kernel_epi_of_zero_of_mono [has_kernels V] [has_zero_object V] [mono g] : epi (image_to_kernel (0 : A ⟶ B) g (by simp))
epi_of_target_iso_zero _ (kernel_subobject_iso g ≪≫ kernel.of_mono g)
instance
image_to_kernel_epi_of_zero_of_mono
algebra.homology
src/algebra/homology/image_to_kernel.lean
[ "category_theory.subobject.limits" ]
[ "image_to_kernel" ]
`image_to_kernel` for `A --0--> B --g--> C`, where `g` is a mono is itself an epi (i.e. the sequence is exact at `B`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83