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prod_to_prod_Top_I {a₁ a₂ : Top.of (ulift I)} {b₁ b₂ : X} (p₁ : from_top a₁ ⟶ from_top a₂) (p₂ : from_top b₁ ⟶ from_top b₂)
@category_theory.functor.map _ _ _ _ (prod_to_prod_Top (Top.of $ ulift I) X) (a₁, b₁) (a₂, b₂) (p₁, p₂)
abbreviation
continuous_map.homotopy.prod_to_prod_Top_I
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "Top.of", "from_top" ]
An abbreviation for `prod_to_prod_Top`, with some types already in place to help the typechecker. In particular, the first path should be on the ulifted unit interval.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diagonal_path : from_top (H (0, x₀)) ⟶ from_top (H (1, x₁))
(πₘ H.ulift_map).map (prod_to_prod_Top_I uhpath01 p)
def
continuous_map.homotopy.diagonal_path
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "from_top" ]
The diagonal path `d` of a homotopy `H` on a path `p`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diagonal_path' : from_top (f x₀) ⟶ from_top (g x₁)
hcast (H.apply_zero x₀).symm ≫ (H.diagonal_path p) ≫ hcast (H.apply_one x₁)
def
continuous_map.homotopy.diagonal_path'
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "from_top" ]
The diagonal path, but starting from `f x₀` and going to `g x₁`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_zero_path : (πₘ f).map p = hcast (H.apply_zero x₀).symm ≫ (πₘ H.ulift_map).map (prod_to_prod_Top_I (𝟙 (ulift.up 0)) p) ≫ hcast (H.apply_zero x₁)
begin apply quotient.induction_on p, intro p', apply @eq_path_of_eq_image _ _ _ _ H.ulift_map _ _ _ _ _ ((path.refl (ulift.up _)).prod p'), simp, end
lemma
continuous_map.homotopy.apply_zero_path
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "path.refl" ]
Proof that `f(p) = H(0 ⟶ 0, p)`, with the appropriate casts
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_one_path : (πₘ g).map p = hcast (H.apply_one x₀).symm ≫ ((πₘ H.ulift_map).map (prod_to_prod_Top_I (𝟙 (ulift.up 1)) p)) ≫ hcast (H.apply_one x₁)
begin apply quotient.induction_on p, intro p', apply @eq_path_of_eq_image _ _ _ _ H.ulift_map _ _ _ _ _ ((path.refl (ulift.up _)).prod p'), simp, end
lemma
continuous_map.homotopy.apply_one_path
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "path.refl" ]
Proof that `g(p) = H(1 ⟶ 1, p)`, with the appropriate casts
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eval_at_eq (x : X) : ⟦H.eval_at x⟧ = hcast (H.apply_zero x).symm ≫ (πₘ H.ulift_map).map (prod_to_prod_Top_I uhpath01 (𝟙 x)) ≫ hcast (H.apply_one x).symm.symm
begin dunfold prod_to_prod_Top_I uhpath01 hcast, refine (@functor.conj_eq_to_hom_iff_heq (πₓ Y) _ _ _ _ _ _ _ _ _).mpr _, simp only [id_eq_path_refl, prod_to_prod_Top_map, path.homotopic.prod_lift, map_eq, ← path.homotopic.map_lift], apply path.homotopic.hpath_hext, intro, refl, end
lemma
continuous_map.homotopy.eval_at_eq
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "id_eq_path_refl", "map_eq", "path.homotopic.hpath_hext", "path.homotopic.map_lift", "path.homotopic.prod_lift" ]
Proof that `H.eval_at x = H(0 ⟶ 1, x ⟶ x)`, with the appropriate casts
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_diag_path : (πₘ f).map p ≫ ⟦H.eval_at x₁⟧ = H.diagonal_path' p ∧ (⟦H.eval_at x₀⟧ ≫ (πₘ g).map p : from_top (f x₀) ⟶ from_top (g x₁)) = H.diagonal_path' p
begin rw [H.apply_zero_path, H.apply_one_path, H.eval_at_eq, H.eval_at_eq], dunfold prod_to_prod_Top_I, split; { slice_lhs 2 5 { simp [← category_theory.functor.map_comp], }, refl, }, end
lemma
continuous_map.homotopy.eq_diag_path
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "from_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homotopic_maps_nat_iso : πₘ f ⟶ πₘ g
{ app := λ x, ⟦H.eval_at x⟧, naturality' := λ x y p, by rw [(H.eq_diag_path p).1, (H.eq_diag_path p).2] }
def
fundamental_groupoid_functor.homotopic_maps_nat_iso
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[]
Given a homotopy H : f ∼ g, we have an associated natural isomorphism between the induced functors `f` and `g`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equiv_of_homotopy_equiv (hequiv : X ≃ₕ Y) : πₓ X ≌ πₓ Y
begin apply equivalence.mk (πₘ hequiv.to_fun : πₓ X ⥤ πₓ Y) (πₘ hequiv.inv_fun : πₓ Y ⥤ πₓ X); simp only [Groupoid.hom_to_functor, Groupoid.id_to_functor], { convert (as_iso (homotopic_maps_nat_iso hequiv.left_inv.some)).symm, exacts [((π).map_id X).symm, ((π).map_comp _ _).symm] }, { convert as_iso...
def
fundamental_groupoid_functor.equiv_of_homotopy_equiv
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/induced_maps.lean
[ "topology.homotopy.equiv", "category_theory.equivalence", "algebraic_topology.fundamental_groupoid.product" ]
[ "map_comp", "map_id" ]
Homotopy equivalent topological spaces have equivalent fundamental groupoids.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj (i : I) : πₓ (Top.of (Π i, X i)) ⥤ πₓ (X i)
πₘ ⟨_, continuous_apply i⟩
def
fundamental_groupoid_functor.proj
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "continuous_apply" ]
The projection map Π i, X i → X i induces a map π(Π i, X i) ⟶ π(X i).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj_map (i : I) (x₀ x₁ : πₓ (Top.of (Π i, X i))) (p : x₀ ⟶ x₁) : (proj X i).map p = (@path.homotopic.proj _ _ _ _ _ i p)
rfl
lemma
fundamental_groupoid_functor.proj_map
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "path.homotopic.proj" ]
The projection map is precisely path.homotopic.proj interpreted as a functor
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_to_pi_Top : (Π i, πₓ (X i)) ⥤ πₓ (Top.of (Π i, X i))
{ obj := λ g, g, map := λ v₁ v₂ p, path.homotopic.pi p, map_id' := begin intro x, change path.homotopic.pi (λ i, 𝟙 (x i)) = _, simp only [fundamental_groupoid.id_eq_path_refl, path.homotopic.pi_lift], refl, end, map_comp' := λ x y z f g, (path.homotopic.comp_pi_eq_pi_comp f g).symm, }
def
fundamental_groupoid_functor.pi_to_pi_Top
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "path.homotopic.comp_pi_eq_pi_comp", "path.homotopic.pi", "path.homotopic.pi_lift" ]
The map taking the pi product of a family of fundamental groupoids to the fundamental groupoid of the pi product. This is actually an isomorphism (see `pi_iso`)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_iso : category_theory.Groupoid.of (Π i : I, πₓ (X i)) ≅ πₓ (Top.of (Π i, X i))
{ hom := pi_to_pi_Top X, inv := category_theory.functor.pi' (proj X), hom_inv_id' := begin change pi_to_pi_Top X ⋙ (category_theory.functor.pi' (proj X)) = 𝟭 _, apply category_theory.functor.ext; intros, { ext, simp, }, { refl, }, end, inv_hom_id' := begin change (category_theory.functor.pi...
def
fundamental_groupoid_functor.pi_iso
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "category_theory.Groupoid.of", "category_theory.functor.ext", "category_theory.functor.pi'", "path.homotopic.pi" ]
Shows `pi_to_pi_Top` is an isomorphism, whose inverse is precisely the pi product of the induced projections. This shows that `fundamental_groupoid_functor` preserves products.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_discrete_comp : limits.cone (discrete.functor X ⋙ π) ≌ limits.cone (discrete.functor (λ i, πₓ (X i)))
limits.cones.postcompose_equivalence (discrete.comp_nat_iso_discrete X π)
def
fundamental_groupoid_functor.cone_discrete_comp
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[]
Equivalence between the categories of cones over the objects `π Xᵢ` written in two ways
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cone_discrete_comp_obj_map_cone : (cone_discrete_comp X).functor.obj ((π).map_cone (Top.pi_fan.{u} X)) = limits.fan.mk (πₓ (Top.of (Π i, X i))) (proj X)
rfl
lemma
fundamental_groupoid_functor.cone_discrete_comp_obj_map_cone
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_Top_to_pi_cone : (limits.fan.mk (πₓ (Top.of (Π i, X i))) (proj X)) ⟶ Groupoid.pi_limit_fan (λ i : I, (πₓ (X i)))
{ hom := category_theory.functor.pi' (proj X) }
def
fundamental_groupoid_functor.pi_Top_to_pi_cone
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "category_theory.functor.pi'" ]
This is `pi_iso.inv` as a cone morphism (in fact, isomorphism)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preserves_product : limits.preserves_limit (discrete.functor X) π
begin apply limits.preserves_limit_of_preserves_limit_cone (Top.pi_fan_is_limit.{u} X), apply (limits.is_limit.of_cone_equiv (cone_discrete_comp X)).to_fun, simp only [cone_discrete_comp_obj_map_cone], apply limits.is_limit.of_iso_limit _ (as_iso (pi_Top_to_pi_cone X)).symm, exact Groupoid.pi_limit_fan_is_lim...
def
fundamental_groupoid_functor.preserves_product
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[]
The fundamental groupoid functor preserves products
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj_left : πₓ (Top.of (A × B)) ⥤ πₓ A
πₘ ⟨_, continuous_fst⟩
def
fundamental_groupoid_functor.proj_left
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of" ]
The induced map of the left projection map X × Y → X
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj_right : πₓ (Top.of (A × B)) ⥤ πₓ B
πₘ ⟨_, continuous_snd⟩
def
fundamental_groupoid_functor.proj_right
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of" ]
The induced map of the right projection map X × Y → Y
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj_left_map (x₀ x₁ : πₓ (Top.of (A × B))) (p : x₀ ⟶ x₁) : (proj_left A B).map p = path.homotopic.proj_left p
rfl
lemma
fundamental_groupoid_functor.proj_left_map
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "path.homotopic.proj_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
proj_right_map (x₀ x₁ : πₓ (Top.of (A × B))) (p : x₀ ⟶ x₁) : (proj_right A B).map p = path.homotopic.proj_right p
rfl
lemma
fundamental_groupoid_functor.proj_right_map
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "path.homotopic.proj_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_to_prod_Top : (πₓ A) × (πₓ B) ⥤ πₓ (Top.of (A × B))
{ obj := λ g, g, map := λ x y p, match x, y, p with | (x₀, x₁), (y₀, y₁), (p₀, p₁) := path.homotopic.prod p₀ p₁ end, map_id' := begin rintro ⟨x₀, x₁⟩, simp only [category_theory.prod_id, fundamental_groupoid.id_eq_path_refl], unfold_aux, rw path.homotopic.prod_lift, refl, end, map_comp' := λ...
def
fundamental_groupoid_functor.prod_to_prod_Top
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "category_theory.prod_id", "path.homotopic.comp_prod_eq_prod_comp", "path.homotopic.prod", "path.homotopic.prod_lift" ]
The map taking the product of two fundamental groupoids to the fundamental groupoid of the product of the two topological spaces. This is in fact an isomorphism (see `prod_iso`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_to_prod_Top_map {x₀ x₁ : πₓ A} {y₀ y₁ : πₓ B} (p₀ : x₀ ⟶ x₁) (p₁ : y₀ ⟶ y₁) : @category_theory.functor.map _ _ _ _ (prod_to_prod_Top A B) (x₀, y₀) (x₁, y₁) (p₀, p₁) = path.homotopic.prod p₀ p₁
rfl
lemma
fundamental_groupoid_functor.prod_to_prod_Top_map
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "path.homotopic.prod" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_iso : category_theory.Groupoid.of ((πₓ A) × (πₓ B)) ≅ (πₓ (Top.of (A × B)))
{ hom := prod_to_prod_Top A B, inv := (proj_left A B).prod' (proj_right A B), hom_inv_id' := begin change prod_to_prod_Top A B ⋙ ((proj_left A B).prod' (proj_right A B)) = 𝟭 _, apply category_theory.functor.hext, { intros, ext; simp; refl, }, rintros ⟨x₀, x₁⟩ ⟨y₀, y₁⟩ ⟨f₀, f₁⟩, have := and.intro ...
def
fundamental_groupoid_functor.prod_iso
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/product.lean
[ "category_theory.groupoid", "algebraic_topology.fundamental_groupoid.basic", "topology.category.Top.limits.products", "topology.homotopy.product" ]
[ "Top.of", "category_theory.Groupoid.of", "category_theory.functor.hext", "path.homotopic.prod_proj_left_proj_right", "path.homotopic.proj_left_prod", "path.homotopic.proj_right_prod" ]
Shows `prod_to_prod_Top` is an isomorphism, whose inverse is precisely the product of the induced left and right projections.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
punit_equiv_discrete_punit : fundamental_groupoid punit.{u+1} ≌ discrete punit.{v+1}
equivalence.mk (functor.star _) ((category_theory.functor.const _).obj punit.star) (nat_iso.of_components (λ _, eq_to_iso dec_trivial) (λ _ _ _, dec_trivial)) (functor.punit_ext _ _)
def
fundamental_groupoid.punit_equiv_discrete_punit
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/punit.lean
[ "category_theory.punit", "algebraic_topology.fundamental_groupoid.basic" ]
[ "category_theory.functor.const", "fundamental_groupoid" ]
Equivalence of groupoids between fundamental groupoid of punit and punit
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simply_connected_space (X : Type*) [topological_space X] : Prop
(equiv_unit [] : nonempty (fundamental_groupoid X ≌ discrete unit))
class
simply_connected_space
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "fundamental_groupoid", "topological_space" ]
A simply connected space is one whose fundamental groupoid is equivalent to `discrete unit`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simply_connected_def (X : Type*) [topological_space X] : simply_connected_space X ↔ nonempty (fundamental_groupoid X ≌ discrete unit)
⟨λ h, @simply_connected_space.equiv_unit X _ h, λ h, ⟨h⟩⟩
lemma
simply_connected_def
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "fundamental_groupoid", "simply_connected_space", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simply_connected_iff_unique_homotopic (X : Type*) [topological_space X] : simply_connected_space X ↔ (nonempty X) ∧ ∀ (x y : X), nonempty (unique (path.homotopic.quotient x y))
by { rw [simply_connected_def, equiv_punit_iff_unique], refl, }
lemma
simply_connected_iff_unique_homotopic
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "path.homotopic.quotient", "simply_connected_def", "simply_connected_space", "topological_space", "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
paths_homotopic {x y : X} (p₁ p₂ : path x y) : path.homotopic p₁ p₂
by simpa using @subsingleton.elim (path.homotopic.quotient x y) _ ⟦p₁⟧ ⟦p₂⟧
lemma
simply_connected_space.paths_homotopic
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "path", "path.homotopic", "path.homotopic.quotient" ]
In a simply connected space, any two paths are homotopic
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_contractible (Y : Type*) [topological_space Y] [contractible_space Y] : simply_connected_space Y
{ equiv_unit := let H : Top.of Y ≃ₕ Top.of unit := (contractible_space.hequiv_unit Y).some in ⟨(fundamental_groupoid_functor.equiv_of_homotopy_equiv H).trans fundamental_groupoid.punit_equiv_discrete_punit⟩, }
instance
simply_connected_space.of_contractible
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "Top.of", "contractible_space", "fundamental_groupoid_functor.equiv_of_homotopy_equiv", "simply_connected_space", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simply_connected_iff_paths_homotopic {Y : Type*} [topological_space Y] : simply_connected_space Y ↔ (path_connected_space Y) ∧ (∀ x y : Y, subsingleton (path.homotopic.quotient x y))
⟨by { introI, split; apply_instance, }, λ h, begin casesI h, rw simply_connected_iff_unique_homotopic, exact ⟨infer_instance, λ x y, ⟨unique_of_subsingleton ⟦path_connected_space.some_path x y⟧⟩⟩, end⟩
lemma
simply_connected_iff_paths_homotopic
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "path.homotopic.quotient", "path_connected_space", "simply_connected_iff_unique_homotopic", "simply_connected_space", "topological_space" ]
A space is simply connected iff it is path connected, and there is at most one path up to homotopy between any two points.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simply_connected_iff_paths_homotopic' {Y : Type*} [topological_space Y] : simply_connected_space Y ↔ (path_connected_space Y) ∧ (∀ {x y : Y} (p₁ p₂ : path x y), path.homotopic p₁ p₂)
begin convert simply_connected_iff_paths_homotopic, simp [path.homotopic.quotient, setoid.eq_top_iff], refl, end
lemma
simply_connected_iff_paths_homotopic'
algebraic_topology.fundamental_groupoid
src/algebraic_topology/fundamental_groupoid/simply_connected.lean
[ "algebraic_topology.fundamental_groupoid.induced_maps", "topology.homotopy.contractible", "category_theory.punit", "algebraic_topology.fundamental_groupoid.punit" ]
[ "path", "path.homotopic", "path.homotopic.quotient", "path_connected_space", "setoid.eq_top_iff", "simply_connected_iff_paths_homotopic", "simply_connected_space", "topological_space" ]
Another version of `simply_connected_iff_paths_homotopic`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
evariation_on (f : α → E) (s : set α) : ℝ≥0∞
⨆ (p : ℕ × {u : ℕ → α // monotone u ∧ ∀ i, u i ∈ s}), ∑ i in finset.range p.1, edist (f ((p.2 : ℕ → α) (i+1))) (f ((p.2 : ℕ → α) i))
def
evariation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "finset.range", "monotone" ]
The (extended real valued) variation of a function `f` on a set `s` inside a linear order is the supremum of the sum of `edist (f (u (i+1))) (f (u i))` over all finite increasing sequences `u` in `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_bounded_variation_on (f : α → E) (s : set α)
evariation_on f s ≠ ∞
def
has_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on" ]
A function has bounded variation on a set `s` if its total variation there is finite.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_locally_bounded_variation_on (f : α → E) (s : set α)
∀ a b, a ∈ s → b ∈ s → has_bounded_variation_on f (s ∩ Icc a b)
def
has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_bounded_variation_on" ]
A function has locally bounded variation on a set `s` if, given any interval `[a, b]` with endpoints in `s`, then the function has finite variation on `s ∩ [a, b]`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonempty_monotone_mem {s : set α} (hs : s.nonempty) : nonempty {u // monotone u ∧ ∀ (i : ℕ), u i ∈ s}
begin obtain ⟨x, hx⟩ := hs, exact ⟨⟨λ i, x, λ i j hij, le_rfl, λ i, hx⟩⟩, end
lemma
evariation_on.nonempty_monotone_mem
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "le_rfl", "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_edist_zero_on {f f' : α → E} {s : set α} (h : ∀ ⦃x⦄, x ∈ s → edist (f x) (f' x) = 0) : evariation_on f s = evariation_on f' s
begin dsimp only [evariation_on], congr' 1 with p : 1, congr' 1 with i : 1, rw [edist_congr_right (h $ p.snd.prop.2 (i+1)), edist_congr_left (h $ p.snd.prop.2 i)], end
lemma
evariation_on.eq_of_edist_zero_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "edist_congr_left", "edist_congr_right", "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_eq_on {f f' : α → E} {s : set α} (h : eq_on f f' s) : evariation_on f s = evariation_on f' s
eq_of_edist_zero_on (λ x xs, by rw [h xs, edist_self])
lemma
evariation_on.eq_of_eq_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum_le (f : α → E) {s : set α} (n : ℕ) {u : ℕ → α} (hu : monotone u) (us : ∀ i, u i ∈ s) : ∑ i in finset.range n, edist (f (u (i+1))) (f (u i)) ≤ evariation_on f s
le_supr_of_le ⟨n, u, hu, us⟩ le_rfl
lemma
evariation_on.sum_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "finset.range", "le_rfl", "le_supr_of_le", "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum_le_of_monotone_on_Iic (f : α → E) {s : set α} {n : ℕ} {u : ℕ → α} (hu : monotone_on u (Iic n)) (us : ∀ i ≤ n, u i ∈ s) : ∑ i in finset.range n, edist (f (u (i+1))) (f (u i)) ≤ evariation_on f s
begin let v := λ i, if i ≤ n then u i else u n, have vs : ∀ i, v i ∈ s, { assume i, simp only [v], split_ifs, { exact us i h }, { exact us n le_rfl } }, have hv : monotone v, { apply monotone_nat_of_le_succ (λ i, _), simp only [v], rcases lt_trichotomy i n with hi|rfl|hi, { have : ...
lemma
evariation_on.sum_le_of_monotone_on_Iic
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "finset.mem_range", "finset.range", "le_rfl", "le_zero_iff", "monotone", "monotone_nat_of_le_succ", "monotone_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum_le_of_monotone_on_Icc (f : α → E) {s : set α} {m n : ℕ} {u : ℕ → α} (hu : monotone_on u (Icc m n)) (us : ∀ i ∈ Icc m n, u i ∈ s) : ∑ i in finset.Ico m n, edist (f (u (i+1))) (f (u i)) ≤ evariation_on f s
begin rcases le_or_lt n m with hnm|hmn, { simp only [finset.Ico_eq_empty_of_le hnm, finset.sum_empty, zero_le'] }, let v := λ i, u (m + i), have hv : monotone_on v (Iic (n - m)), { assume a ha b hb hab, simp only [le_tsub_iff_left hmn.le, mem_Iic] at ha hb, exact hu ⟨le_add_right le_rfl, ha⟩ ⟨le_add_r...
lemma
evariation_on.sum_le_of_monotone_on_Icc
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "finset.Ico", "finset.Ico_eq_empty_of_le", "finset.range", "finset.range_eq_Ico", "le_rfl", "le_tsub_iff_left", "monotone_on", "tsub_add_cancel_of_le", "zero_le'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mono (f : α → E) {s t : set α} (hst : t ⊆ s) : evariation_on f t ≤ evariation_on f s
begin apply supr_le _, rintros ⟨n, ⟨u, hu, ut⟩⟩, exact sum_le f n hu (λ i, hst (ut i)), end
lemma
evariation_on.mono
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "supr_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.has_bounded_variation_on.mono {f : α → E} {s : set α} (h : has_bounded_variation_on f s) {t : set α} (ht : t ⊆ s) : has_bounded_variation_on f t
(lt_of_le_of_lt (evariation_on.mono f ht) (lt_top_iff_ne_top.2 h)).ne
lemma
has_bounded_variation_on.mono
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on.mono", "has_bounded_variation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.has_bounded_variation_on.has_locally_bounded_variation_on {f : α → E} {s : set α} (h : has_bounded_variation_on f s) : has_locally_bounded_variation_on f s
λ x y hx hy, h.mono (inter_subset_left _ _)
lemma
has_bounded_variation_on.has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_bounded_variation_on", "has_locally_bounded_variation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_le (f : α → E) {s : set α} {x y : α} (hx : x ∈ s) (hy : y ∈ s) : edist (f x) (f y) ≤ evariation_on f s
begin wlog hxy : x ≤ y, { rw edist_comm, exact this f hy hx (le_of_not_le hxy) }, let u : ℕ → α := λ n, if n = 0 then x else y, have hu : monotone u, { assume m n hmn, dsimp only [u], split_ifs, exacts [le_rfl, hxy, by linarith [pos_iff_ne_zero.2 h], le_rfl] }, have us : ∀ i, u i ∈ s, { as...
lemma
evariation_on.edist_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "le_rfl", "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_iff (f : α → E) {s : set α} : evariation_on f s = 0 ↔ ∀ (x y ∈ s), edist (f x) (f y) = 0
begin split, { rintro h x xs y ys, rw [←le_zero_iff, ←h], exact edist_le f xs ys, }, { rintro h, dsimp only [evariation_on], rw ennreal.supr_eq_zero, rintro ⟨n, u, um, us⟩, exact finset.sum_eq_zero (λ i hi, h _ (us i.succ) _ (us i)), }, end
lemma
evariation_on.eq_zero_iff
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.supr_eq_zero", "eq_zero_iff", "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
constant_on {f : α → E} {s : set α} (hf : (f '' s).subsingleton) : evariation_on f s = 0
begin rw eq_zero_iff, rintro x xs y ys, rw [hf ⟨x, xs, rfl⟩ ⟨y, ys, rfl⟩, edist_self], end
lemma
evariation_on.constant_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "eq_zero_iff", "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsingleton (f : α → E) {s : set α} (hs : s.subsingleton) : evariation_on f s = 0
constant_on (hs.image f)
lemma
evariation_on.subsingleton
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lower_continuous_aux {ι : Type*} {F : ι → α → E} {p : filter ι} {f : α → E} {s : set α} (Ffs : ∀ x ∈ s, tendsto (λ i, F i x) p (𝓝 (f x))) {v : ℝ≥0∞} (hv : v < evariation_on f s) : ∀ᶠ (n : ι) in p, v < evariation_on (F n) s
begin obtain ⟨⟨n, ⟨u, um, us⟩⟩, hlt⟩ : ∃ (p : ℕ × {u : ℕ → α // monotone u ∧ ∀ i, u i ∈ s}), v < ∑ i in finset.range p.1, edist (f ((p.2 : ℕ → α) (i+1))) (f ((p.2 : ℕ → α) i)) := lt_supr_iff.mp hv, have : tendsto (λ j, ∑ (i : ℕ) in finset.range n, edist (F j (u (i + 1))) (F j (u i))) p (𝓝 ...
lemma
evariation_on.lower_continuous_aux
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "eventually_gt_of_tendsto_gt", "filter", "finset.range", "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lower_semicontinuous (s : set α) : lower_semicontinuous (λ f : α →ᵤ[s.image singleton] E, evariation_on f s)
begin intro f, apply @lower_continuous_aux _ _ _ _ (uniform_on_fun α E (s.image singleton)) id (𝓝 f) f s _, simpa only [uniform_on_fun.tendsto_iff_tendsto_uniformly_on, mem_image, forall_exists_index, and_imp, forall_apply_eq_imp_iff₂, tendsto_uniformly_on_singleton_iff_tendsto] using...
lemma
evariation_on.lower_semicontinuous
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "and_imp", "evariation_on", "forall_apply_eq_imp_iff₂", "forall_exists_index", "lower_semicontinuous", "tendsto_uniformly_on_singleton_iff_tendsto", "uniform_on_fun", "uniform_on_fun.tendsto_iff_tendsto_uniformly_on" ]
The map `λ f, evariation_on f s` is lower semicontinuous for pointwise convergence *on `s`*. Pointwise convergence on `s` is encoded here as uniform convergence on the family consisting of the singletons of elements of `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lower_semicontinuous_uniform_on (s : set α) : lower_semicontinuous (λ f : α →ᵤ[{s}] E, evariation_on f s)
begin intro f, apply @lower_continuous_aux _ _ _ _ (uniform_on_fun α E {s}) id (𝓝 f) f s _, have := @tendsto_id _ (𝓝 f), rw uniform_on_fun.tendsto_iff_tendsto_uniformly_on at this, simp_rw ←tendsto_uniformly_on_singleton_iff_tendsto, exact λ x xs, ((this s rfl).mono (singleton_subset_iff.mpr xs)), end
lemma
evariation_on.lower_semicontinuous_uniform_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "lower_semicontinuous", "uniform_on_fun", "uniform_on_fun.tendsto_iff_tendsto_uniformly_on" ]
The map `λ f, evariation_on f s` is lower semicontinuous for uniform convergence on `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.has_bounded_variation_on.dist_le {E : Type*} [pseudo_metric_space E] {f : α → E} {s : set α} (h : has_bounded_variation_on f s) {x y : α} (hx : x ∈ s) (hy : y ∈ s) : dist (f x) (f y) ≤ (evariation_on f s).to_real
begin rw [← ennreal.of_real_le_of_real_iff ennreal.to_real_nonneg, ennreal.of_real_to_real h, ← edist_dist], exact edist_le f hx hy end
lemma
has_bounded_variation_on.dist_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "edist_dist", "ennreal.of_real_le_of_real_iff", "ennreal.of_real_to_real", "ennreal.to_real_nonneg", "evariation_on", "has_bounded_variation_on", "pseudo_metric_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.has_bounded_variation_on.sub_le {f : α → ℝ} {s : set α} (h : has_bounded_variation_on f s) {x y : α} (hx : x ∈ s) (hy : y ∈ s) : f x - f y ≤ (evariation_on f s).to_real
begin apply (le_abs_self _).trans, rw ← real.dist_eq, exact h.dist_le hx hy end
lemma
has_bounded_variation_on.sub_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "has_bounded_variation_on", "le_abs_self", "real.dist_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_point (f : α → E) {s : set α} {x : α} (hx : x ∈ s) (u : ℕ → α) (hu : monotone u) (us : ∀ i, u i ∈ s) (n : ℕ) : ∃ (v : ℕ → α) (m : ℕ), monotone v ∧ (∀ i, v i ∈ s) ∧ x ∈ v '' (Iio m) ∧ ∑ i in finset.range n, edist (f (u (i+1))) (f (u i)) ≤ ∑ j in finset.range m, edist (f (v (j+1))) (f (v j))
begin rcases le_or_lt (u n) x with h|h, { let v := λ i, if i ≤ n then u i else x, have vs : ∀ i, v i ∈ s, { assume i, simp only [v], split_ifs, { exact us i }, { exact hx } }, have hv : monotone v, { apply monotone_nat_of_le_succ (λ i, _), simp only [v], rcases lt...
lemma
evariation_on.add_point
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "eq_or_lt_of_le", "finset.Ico", "finset.Ico_self", "finset.Ico_subset_Ico", "finset.mem_Ico", "finset.mem_range", "finset.range", "finset.range_eq_Ico", "finset.range_mono", "finset.sum_eq_sum_Ico_succ_bot", "is_empty.forall_iff", "ite_eq_right_iff", "le_rfl", "le_zero_iff", "monotone", ...
Consider a monotone function `u` parameterizing some points of a set `s`. Given `x ∈ s`, then one can find another monotone function `v` parameterizing the same points as `u`, with `x` added. In particular, the variation of a function along `u` is bounded by its variation along `v`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_le_union (f : α → E) {s t : set α} (h : ∀ x ∈ s, ∀ y ∈ t, x ≤ y) : evariation_on f s + evariation_on f t ≤ evariation_on f (s ∪ t)
begin by_cases hs : s = ∅, { simp [hs] }, haveI : nonempty {u // monotone u ∧ ∀ (i : ℕ), u i ∈ s}, from nonempty_monotone_mem (nonempty_iff_ne_empty.2 hs), by_cases ht : t = ∅, { simp [ht] }, haveI : nonempty {u // monotone u ∧ ∀ (i : ℕ), u i ∈ t}, from nonempty_monotone_mem (nonempty_iff_ne_empty.2...
lemma
evariation_on.add_le_union
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "add_tsub_cancel_left", "ennreal.supr_add_supr_le", "evariation_on", "finset.Ico", "finset.mem_Ico", "finset.mem_range", "finset.mem_union", "finset.range", "finset.range_eq_Ico", "le_rfl", "monotone", "tsub_eq_iff_eq_add_of_le", "tsub_le_tsub" ]
The variation of a function on the union of two sets `s` and `t`, with `s` to the left of `t`, bounds the sum of the variations along `s` and `t`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
union (f : α → E) {s t : set α} {x : α} (hs : is_greatest s x) (ht : is_least t x) : evariation_on f (s ∪ t) = evariation_on f s + evariation_on f t
begin classical, apply le_antisymm _ (evariation_on.add_le_union f (λ a ha b hb, le_trans (hs.2 ha) (ht.2 hb))), apply supr_le _, rintros ⟨n, ⟨u, hu, ust⟩⟩, obtain ⟨v, m, hv, vst, xv, huv⟩ : ∃ (v : ℕ → α) (m : ℕ), monotone v ∧ (∀ i, v i ∈ s ∪ t) ∧ x ∈ v '' (Iio m) ∧ ∑ i in finset.range n, edist (f (u (i+1...
lemma
evariation_on.union
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "evariation_on.add_le_union", "evariation_on.add_point", "finset.Ico", "finset.range", "finset.range_eq_Ico", "is_greatest", "is_least", "monotone", "supr_le" ]
If a set `s` is to the left of a set `t`, and both contain the boundary point `x`, then the variation of `f` along `s ∪ t` is the sum of the variations.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Icc_add_Icc (f : α → E) {s : set α} {a b c : α} (hab : a ≤ b) (hbc : b ≤ c) (hb : b ∈ s) : evariation_on f (s ∩ Icc a b) + evariation_on f (s ∩ Icc b c) = evariation_on f (s ∩ Icc a c)
begin have A : is_greatest (s ∩ Icc a b) b := ⟨⟨hb, hab, le_rfl⟩, (inter_subset_right _ _).trans (Icc_subset_Iic_self)⟩, have B : is_least (s ∩ Icc b c) b := ⟨⟨hb, le_rfl, hbc⟩, (inter_subset_right _ _).trans (Icc_subset_Ici_self)⟩, rw [← evariation_on.union f A B, ← inter_union_distrib_left, Icc_union_Ic...
lemma
evariation_on.Icc_add_Icc
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "evariation_on.union", "is_greatest", "is_least", "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_le_of_monotone_on (f : α → E) {s : set α} {t : set β} (φ : β → α) (hφ : monotone_on φ t) (φst : maps_to φ t s) : evariation_on (f ∘ φ) t ≤ evariation_on f s
supr_le $ λ ⟨n, u, hu, ut⟩, le_supr_of_le ⟨n, φ ∘ u, λ x y xy, hφ (ut x) (ut y) (hu xy), λ i, φst (ut i)⟩ le_rfl
lemma
evariation_on.comp_le_of_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "le_rfl", "le_supr_of_le", "monotone_on", "supr_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_le_of_antitone_on (f : α → E) {s : set α} {t : set β} (φ : β → α) (hφ : antitone_on φ t) (φst : maps_to φ t s) : evariation_on (f ∘ φ) t ≤ evariation_on f s
begin refine supr_le _, rintro ⟨n, u, hu, ut⟩, rw ←finset.sum_range_reflect, refine (finset.sum_congr rfl $ λ x hx, _).trans_le (le_supr_of_le ⟨n, λ i, φ (u $ n-i), λ x y xy, hφ (ut _) (ut _) (hu $ n.sub_le_sub_left xy), λ i, φst (ut _)⟩ le_rfl), dsimp only [subtype.coe_mk], rw [edist_comm, nat.sub_sub,...
lemma
evariation_on.comp_le_of_antitone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "antitone_on", "evariation_on", "finset.mem_range", "le_rfl", "le_supr_of_le", "subtype.coe_mk", "supr_le", "tsub_pos_iff_lt" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_eq_of_monotone_on (f : α → E) {t : set β} (φ : β → α) (hφ : monotone_on φ t) : evariation_on (f ∘ φ) t = evariation_on f (φ '' t)
begin apply le_antisymm (comp_le_of_monotone_on f φ hφ (maps_to_image φ t)), casesI is_empty_or_nonempty β, { convert zero_le _, exact evariation_on.subsingleton f ((subsingleton_of_subsingleton.image _).anti (surj_on_image φ t)) }, let ψ := φ.inv_fun_on t, have ψφs : eq_on (φ ∘ ψ) id (φ '' t)...
lemma
evariation_on.comp_eq_of_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "evariation_on.subsingleton", "function.monotone_on_of_right_inv_on_of_maps_to", "is_empty_or_nonempty", "monotone_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.set.subsingleton_Icc_of_ge {α : Type*} [partial_order α] {a b : α} (h : b ≤ a) : set.subsingleton (Icc a b)
begin rintros c ⟨ac,cb⟩ d ⟨ad,db⟩, cases le_antisymm (cb.trans h) ac, cases le_antisymm (db.trans h) ad, refl, end
lemma
set.subsingleton_Icc_of_ge
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "set.subsingleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_inter_Icc_eq_of_monotone_on (f : α → E) {t : set β} (φ : β → α) (hφ : monotone_on φ t) {x y : β} (hx : x ∈ t) (hy : y ∈ t) : evariation_on (f ∘ φ) (t ∩ Icc x y) = evariation_on f ((φ '' t) ∩ Icc (φ x) (φ y))
begin rcases le_total x y with h|h, { convert comp_eq_of_monotone_on f φ (hφ.mono (set.inter_subset_left t (Icc x y))), apply le_antisymm, { rintro _ ⟨⟨u, us, rfl⟩, vφx, vφy⟩, rcases le_total x u with xu|ux, { rcases le_total u y with uy|yu, { exact ⟨u, ⟨us, ⟨xu, uy⟩⟩, rfl⟩, }, {...
lemma
evariation_on.comp_inter_Icc_eq_of_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "evariation_on.subsingleton", "monotone_on", "set.inter_subset_left", "set.inter_subset_right", "set.subsingleton_Icc_of_ge" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_eq_of_antitone_on (f : α → E) {t : set β} (φ : β → α) (hφ : antitone_on φ t) : evariation_on (f ∘ φ) t = evariation_on f (φ '' t)
begin apply le_antisymm (comp_le_of_antitone_on f φ hφ (maps_to_image φ t)), casesI is_empty_or_nonempty β, { convert zero_le _, exact evariation_on.subsingleton f ((subsingleton_of_subsingleton.image _).anti (surj_on_image φ t)) }, let ψ := φ.inv_fun_on t, have ψφs : eq_on (φ ∘ ψ) id (φ '' t) := (s...
lemma
evariation_on.comp_eq_of_antitone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "antitone_on", "evariation_on", "evariation_on.subsingleton", "function.antitone_on_of_right_inv_on_of_maps_to", "is_empty_or_nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_of_dual (f : α → E) (s : set α) : evariation_on (f ∘ of_dual) (of_dual ⁻¹' s) = evariation_on f s
begin convert comp_eq_of_antitone_on f of_dual (λ _ _ _ _, id), simp only [equiv.image_preimage], end
lemma
evariation_on.comp_of_dual
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "equiv.image_preimage", "evariation_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
monotone_on.evariation_on_le {f : α → ℝ} {s : set α} (hf : monotone_on f s) {a b : α} (as : a ∈ s) (bs : b ∈ s) : evariation_on f (s ∩ Icc a b) ≤ ennreal.of_real (f b - f a)
begin apply supr_le _, rintros ⟨n, ⟨u, hu, us⟩⟩, calc ∑ i in finset.range n, edist (f (u (i+1))) (f (u i)) = ∑ i in finset.range n, ennreal.of_real (f (u (i + 1)) - f (u i)) : begin apply finset.sum_congr rfl (λ i hi, _), simp only [finset.mem_range] at hi, rw [edist_dist, real.dist_...
lemma
monotone_on.evariation_on_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "abs_of_nonneg", "edist_dist", "ennreal.of_real", "ennreal.of_real_le_of_real", "ennreal.of_real_sum_of_nonneg", "evariation_on", "finset.mem_range", "finset.range", "monotone_on", "real.dist_eq", "supr_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
monotone_on.has_locally_bounded_variation_on {f : α → ℝ} {s : set α} (hf : monotone_on f s) : has_locally_bounded_variation_on f s
λ a b as bs, ((hf.evariation_on_le as bs).trans_lt ennreal.of_real_lt_top).ne
lemma
monotone_on.has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.of_real_lt_top", "has_locally_bounded_variation_on", "monotone_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
variation_on_from_to (f : α → E) (s : set α) (a b : α) : ℝ
if a ≤ b then (evariation_on f (s ∩ Icc a b)).to_real else - (evariation_on f (s ∩ Icc b a)).to_real
def
variation_on_from_to
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on" ]
The **signed** variation of `f` on the interval `Icc a b` intersected with the set `s`, squashed to a real (therefore only really meaningful if the variation is finite)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
self (a : α) : variation_on_from_to f s a a = 0
begin dsimp only [variation_on_from_to], rw [if_pos le_rfl, Icc_self, evariation_on.subsingleton, ennreal.zero_to_real], exact λ x hx y hy, hx.2.trans hy.2.symm, end
lemma
variation_on_from_to.self
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.zero_to_real", "evariation_on.subsingleton", "le_rfl", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonneg_of_le {a b : α} (h : a ≤ b) : 0 ≤ variation_on_from_to f s a b
by simp only [variation_on_from_to, if_pos h, ennreal.to_real_nonneg]
lemma
variation_on_from_to.nonneg_of_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.to_real_nonneg", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_neg_swap (a b : α) : variation_on_from_to f s a b = - variation_on_from_to f s b a
begin rcases lt_trichotomy a b with ab|rfl|ba, { simp only [variation_on_from_to, if_pos ab.le, if_neg ab.not_le, neg_neg], }, { simp only [self, neg_zero], }, { simp only [variation_on_from_to, if_pos ba.le, if_neg ba.not_le, neg_neg], }, end
lemma
variation_on_from_to.eq_neg_swap
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nonpos_of_ge {a b : α} (h : b ≤ a) : variation_on_from_to f s a b ≤ 0
begin rw eq_neg_swap, exact neg_nonpos_of_nonneg (nonneg_of_le f s h), end
lemma
variation_on_from_to.nonpos_of_ge
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_le {a b : α} (h : a ≤ b) : variation_on_from_to f s a b = (evariation_on f (s ∩ Icc a b)).to_real
if_pos h
lemma
variation_on_from_to.eq_of_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_ge {a b : α} (h : b ≤ a) : variation_on_from_to f s a b = - (evariation_on f (s ∩ Icc b a)).to_real
by rw [eq_neg_swap, neg_inj, eq_of_le f s h]
lemma
variation_on_from_to.eq_of_ge
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b c : α} (ha : a ∈ s) (hb : b ∈ s) (hc : c ∈ s) : variation_on_from_to f s a b + variation_on_from_to f s b c = variation_on_from_to f s a c
begin symmetry, refine additive_of_is_total (≤) (variation_on_from_to f s) (∈s) _ _ ha hb hc, { rintro x y xs ys, simp only [eq_neg_swap f s y x, subtype.coe_mk, add_right_neg, forall_true_left], }, { rintro x y z xy yz xs ys zs, rw [eq_of_le f s xy, eq_of_le f s yz, eq_of_le f s (xy.trans yz), ...
lemma
variation_on_from_to.add
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on.Icc_add_Icc", "forall_true_left", "has_locally_bounded_variation_on", "subtype.coe_mk", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_zero_of_eq_zero {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) (h : variation_on_from_to f s a b = 0) : edist (f a) (f b) = 0
begin wlog h' : a ≤ b, { rw edist_comm, apply this hf hb ha _ (le_of_not_le h'), rw [eq_neg_swap, h, neg_zero] }, { apply le_antisymm _ (zero_le _), rw [←ennreal.of_real_zero, ←h, eq_of_le f s h', ennreal.of_real_to_real (hf a b ha hb)], apply evariation_on.edist_le, exacts [⟨ha, ⟨le_rfl, h'⟩⟩...
lemma
variation_on_from_to.edist_zero_of_eq_zero
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.of_real_to_real", "evariation_on.edist_le", "has_locally_bounded_variation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_left_iff {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b c : α} (ha : a ∈ s) (hb : b ∈ s) (hc : c ∈ s) : variation_on_from_to f s a b = variation_on_from_to f s a c ↔ variation_on_from_to f s b c = 0
by simp only [←add hf ha hb hc, self_eq_add_right]
lemma
variation_on_from_to.eq_left_iff
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_iff_of_le {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) (ab : a ≤ b) : variation_on_from_to f s a b = 0 ↔ ∀ ⦃x⦄ (hx : x ∈ s ∩ Icc a b) ⦃y⦄ (hy : y ∈ s ∩ Icc a b), edist (f x) (f y) = 0
by rw [eq_of_le _ _ ab, ennreal.to_real_eq_zero_iff, or_iff_left (hf a b ha hb), evariation_on.eq_zero_iff]
lemma
variation_on_from_to.eq_zero_iff_of_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.to_real_eq_zero_iff", "evariation_on.eq_zero_iff", "has_locally_bounded_variation_on", "or_iff_left", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_iff_of_ge {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) (ba : b ≤ a) : variation_on_from_to f s a b = 0 ↔ ∀ ⦃x⦄ (hx : x ∈ s ∩ Icc b a) ⦃y⦄ (hy : y ∈ s ∩ Icc b a), edist (f x) (f y) = 0
by rw [eq_of_ge _ _ ba, neg_eq_zero, ennreal.to_real_eq_zero_iff, or_iff_left (hf b a hb ha), evariation_on.eq_zero_iff]
lemma
variation_on_from_to.eq_zero_iff_of_ge
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.to_real_eq_zero_iff", "evariation_on.eq_zero_iff", "has_locally_bounded_variation_on", "or_iff_left", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_iff {f : α → E} {s : set α} (hf : has_locally_bounded_variation_on f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) : variation_on_from_to f s a b = 0 ↔ ∀ ⦃x⦄ (hx : x ∈ s ∩ uIcc a b) ⦃y⦄ (hy : y ∈ s ∩ uIcc a b), edist (f x) (f y) = 0
begin rcases le_total a b with ab|ba, { rw uIcc_of_le ab, exact eq_zero_iff_of_le hf ha hb ab, }, { rw uIcc_of_ge ba, exact eq_zero_iff_of_ge hf ha hb ba, }, end
lemma
variation_on_from_to.eq_zero_iff
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "eq_zero_iff", "has_locally_bounded_variation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
monotone_on (hf : has_locally_bounded_variation_on f s) {a : α} (as : a ∈ s) : monotone_on (variation_on_from_to f s a) s
begin rintro b bs c cs bc, rw ←add hf as bs cs, exact le_add_of_nonneg_right (nonneg_of_le f s bc), end
lemma
variation_on_from_to.monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "monotone_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
antitone_on (hf : has_locally_bounded_variation_on f s) {b : α} (bs : b ∈ s) : antitone_on (λ a, variation_on_from_to f s a b) s
begin rintro a as c cs ac, dsimp only, rw ←add hf as cs bs, exact le_add_of_nonneg_left (nonneg_of_le f s ac), end
lemma
variation_on_from_to.antitone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "antitone_on", "has_locally_bounded_variation_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_self_monotone_on {f : α → ℝ} {s : set α} (hf : has_locally_bounded_variation_on f s) {a : α} (as : a ∈ s) : monotone_on (variation_on_from_to f s a - f) s
begin rintro b bs c cs bc, rw [pi.sub_apply, pi.sub_apply, le_sub_iff_add_le, add_comm_sub, ← le_sub_iff_add_le'], calc f c - f b ≤ |f c - f b| : le_abs_self _ ... = dist (f b) (f c) : by rw [dist_comm, real.dist_eq] ... ≤ variation_on_from_to f s b c : by { rw [eq_of_le f s bc, dist_edist], appl...
lemma
variation_on_from_to.sub_self_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "dist_comm", "dist_edist", "ennreal.to_real_mono", "evariation_on.edist_le", "has_locally_bounded_variation_on", "le_abs_self", "le_rfl", "monotone_on", "real.dist_eq", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_eq_of_monotone_on (f : α → E) {t : set β} (φ : β → α) (hφ : monotone_on φ t) {x y : β} (hx : x ∈ t) (hy : y ∈ t) : variation_on_from_to (f ∘ φ) t x y = variation_on_from_to f (φ '' t) (φ x) (φ y)
begin rcases le_total x y with h|h, { rw [eq_of_le _ _ h, eq_of_le _ _ (hφ hx hy h), evariation_on.comp_inter_Icc_eq_of_monotone_on f φ hφ hx hy], }, { rw [eq_of_ge _ _ h, eq_of_ge _ _ (hφ hy hx h), evariation_on.comp_inter_Icc_eq_of_monotone_on f φ hφ hy hx], }, end
lemma
variation_on_from_to.comp_eq_of_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on.comp_inter_Icc_eq_of_monotone_on", "monotone_on", "variation_on_from_to" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_locally_bounded_variation_on.exists_monotone_on_sub_monotone_on {f : α → ℝ} {s : set α} (h : has_locally_bounded_variation_on f s) : ∃ (p q : α → ℝ), monotone_on p s ∧ monotone_on q s ∧ f = p - q
begin rcases eq_empty_or_nonempty s with rfl|⟨c, cs⟩, { exact ⟨f, 0, subsingleton_empty.monotone_on _, subsingleton_empty.monotone_on _, (sub_zero f).symm⟩ }, { exact ⟨_, _, variation_on_from_to.monotone_on h cs, variation_on_from_to.sub_self_monotone_on h cs, (sub_sub_cancel _ _).symm⟩ }, end
lemma
has_locally_bounded_variation_on.exists_monotone_on_sub_monotone_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "monotone_on", "variation_on_from_to.monotone_on", "variation_on_from_to.sub_self_monotone_on" ]
If a real valued function has bounded variation on a set, then it is a difference of monotone functions there.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.comp_evariation_on_le {f : E → F} {C : ℝ≥0} {t : set E} (h : lipschitz_on_with C f t) {g : α → E} {s : set α} (hg : maps_to g s t) : evariation_on (f ∘ g) s ≤ C * evariation_on g s
begin apply supr_le _, rintros ⟨n, ⟨u, hu, us⟩⟩, calc ∑ i in finset.range n, edist (f (g (u (i+1)))) (f (g (u i))) ≤ ∑ i in finset.range n, C * edist (g (u (i+1))) (g (u i)) : finset.sum_le_sum (λ i hi, h (hg (us _)) (hg (us _))) ... = C * ∑ i in finset.range n, edist (g (u (i+1))) (g (u i)) : by rw...
lemma
lipschitz_on_with.comp_evariation_on_le
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "evariation_on", "evariation_on.sum_le", "finset.mul_sum", "finset.range", "lipschitz_on_with", "mul_le_mul_left'", "supr_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.comp_has_bounded_variation_on {f : E → F} {C : ℝ≥0} {t : set E} (hf : lipschitz_on_with C f t) {g : α → E} {s : set α} (hg : maps_to g s t) (h : has_bounded_variation_on g s) : has_bounded_variation_on (f ∘ g) s
ne_top_of_le_ne_top (ennreal.mul_ne_top ennreal.coe_ne_top h) (hf.comp_evariation_on_le hg)
lemma
lipschitz_on_with.comp_has_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "ennreal.coe_ne_top", "ennreal.mul_ne_top", "has_bounded_variation_on", "lipschitz_on_with", "ne_top_of_le_ne_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.comp_has_locally_bounded_variation_on {f : E → F} {C : ℝ≥0} {t : set E} (hf : lipschitz_on_with C f t) {g : α → E} {s : set α} (hg : maps_to g s t) (h : has_locally_bounded_variation_on g s) : has_locally_bounded_variation_on (f ∘ g) s
λ x y xs ys, hf.comp_has_bounded_variation_on (hg.mono_left (inter_subset_left _ _)) (h x y xs ys)
lemma
lipschitz_on_with.comp_has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "lipschitz_on_with" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_with.comp_has_bounded_variation_on {f : E → F} {C : ℝ≥0} (hf : lipschitz_with C f) {g : α → E} {s : set α} (h : has_bounded_variation_on g s) : has_bounded_variation_on (f ∘ g) s
(hf.lipschitz_on_with univ).comp_has_bounded_variation_on (maps_to_univ _ _) h
lemma
lipschitz_with.comp_has_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_bounded_variation_on", "lipschitz_with" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_with.comp_has_locally_bounded_variation_on {f : E → F} {C : ℝ≥0} (hf : lipschitz_with C f) {g : α → E} {s : set α} (h : has_locally_bounded_variation_on g s) : has_locally_bounded_variation_on (f ∘ g) s
(hf.lipschitz_on_with univ).comp_has_locally_bounded_variation_on (maps_to_univ _ _) h
lemma
lipschitz_with.comp_has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "lipschitz_with" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.has_locally_bounded_variation_on {f : ℝ → E} {C : ℝ≥0} {s : set ℝ} (hf : lipschitz_on_with C f s) : has_locally_bounded_variation_on f s
hf.comp_has_locally_bounded_variation_on (maps_to_id _) (@monotone_on_id ℝ _ s).has_locally_bounded_variation_on
lemma
lipschitz_on_with.has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "lipschitz_on_with", "monotone_on_id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_with.has_locally_bounded_variation_on {f : ℝ → E} {C : ℝ≥0} (hf : lipschitz_with C f) (s : set ℝ) : has_locally_bounded_variation_on f s
(hf.lipschitz_on_with s).has_locally_bounded_variation_on
lemma
lipschitz_with.has_locally_bounded_variation_on
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "has_locally_bounded_variation_on", "lipschitz_with" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_differentiable_within_at_of_mem_real {f : ℝ → ℝ} {s : set ℝ} (h : has_locally_bounded_variation_on f s) : ∀ᵐ x, x ∈ s → differentiable_within_at ℝ f s x
begin obtain ⟨p, q, hp, hq, fpq⟩ : ∃ p q, monotone_on p s ∧ monotone_on q s ∧ f = p - q, from h.exists_monotone_on_sub_monotone_on, filter_upwards [hp.ae_differentiable_within_at_of_mem, hq.ae_differentiable_within_at_of_mem] with x hxp hxq xs, have fpq : ∀ x, f x = p x - q x, by simp [fpq], refine ((hx...
theorem
has_locally_bounded_variation_on.ae_differentiable_within_at_of_mem_real
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_within_at", "has_locally_bounded_variation_on", "monotone_on" ]
A bounded variation function into `ℝ` is differentiable almost everywhere. Superseded by `ae_differentiable_within_at_of_mem`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_differentiable_within_at_of_mem_pi {ι : Type*} [fintype ι] {f : ℝ → (ι → ℝ)} {s : set ℝ} (h : has_locally_bounded_variation_on f s) : ∀ᵐ x, x ∈ s → differentiable_within_at ℝ f s x
begin have A : ∀ (i : ι), lipschitz_with 1 (λ (x : ι → ℝ), x i) := λ i, lipschitz_with.eval i, have : ∀ (i : ι), ∀ᵐ x, x ∈ s → differentiable_within_at ℝ (λ (x : ℝ), f x i) s x, { assume i, apply ae_differentiable_within_at_of_mem_real, exact lipschitz_with.comp_has_locally_bounded_variation_on (A i) h },...
theorem
has_locally_bounded_variation_on.ae_differentiable_within_at_of_mem_pi
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_within_at", "fintype", "has_locally_bounded_variation_on", "lipschitz_with", "lipschitz_with.comp_has_locally_bounded_variation_on", "lipschitz_with.eval" ]
A bounded variation function into a finite dimensional product vector space is differentiable almost everywhere. Superseded by `ae_differentiable_within_at_of_mem`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_differentiable_within_at_of_mem {f : ℝ → V} {s : set ℝ} (h : has_locally_bounded_variation_on f s) : ∀ᵐ x, x ∈ s → differentiable_within_at ℝ f s x
begin let A := (basis.of_vector_space ℝ V).equiv_fun.to_continuous_linear_equiv, suffices H : ∀ᵐ x, x ∈ s → differentiable_within_at ℝ (A ∘ f) s x, { filter_upwards [H] with x hx xs, have : f = (A.symm ∘ A) ∘ f, by simp only [continuous_linear_equiv.symm_comp_self, function.comp.left_id], rw this, ...
theorem
has_locally_bounded_variation_on.ae_differentiable_within_at_of_mem
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "basis.of_vector_space", "continuous_linear_equiv.symm_comp_self", "differentiable_within_at", "has_locally_bounded_variation_on" ]
A real function into a finite dimensional real vector space with bounded variation on a set is differentiable almost everywhere in this set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_differentiable_within_at {f : ℝ → V} {s : set ℝ} (h : has_locally_bounded_variation_on f s) (hs : measurable_set s) : ∀ᵐ x ∂(volume.restrict s), differentiable_within_at ℝ f s x
begin rw ae_restrict_iff' hs, exact h.ae_differentiable_within_at_of_mem end
theorem
has_locally_bounded_variation_on.ae_differentiable_within_at
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_within_at", "has_locally_bounded_variation_on", "measurable_set" ]
A real function into a finite dimensional real vector space with bounded variation on a set is differentiable almost everywhere in this set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_differentiable_at {f : ℝ → V} (h : has_locally_bounded_variation_on f univ) : ∀ᵐ x, differentiable_at ℝ f x
begin filter_upwards [h.ae_differentiable_within_at_of_mem] with x hx, rw differentiable_within_at_univ at hx, exact hx (mem_univ _), end
theorem
has_locally_bounded_variation_on.ae_differentiable_at
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_at", "differentiable_within_at_univ", "has_locally_bounded_variation_on" ]
A real function into a finite dimensional real vector space with bounded variation is differentiable almost everywhere.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.ae_differentiable_within_at_of_mem {C : ℝ≥0} {f : ℝ → V} {s : set ℝ} (h : lipschitz_on_with C f s) : ∀ᵐ x, x ∈ s → differentiable_within_at ℝ f s x
h.has_locally_bounded_variation_on.ae_differentiable_within_at_of_mem
lemma
lipschitz_on_with.ae_differentiable_within_at_of_mem
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_within_at", "lipschitz_on_with" ]
A real function into a finite dimensional real vector space which is Lipschitz on a set is differentiable almost everywhere in this set .
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_on_with.ae_differentiable_within_at {C : ℝ≥0} {f : ℝ → V} {s : set ℝ} (h : lipschitz_on_with C f s) (hs : measurable_set s) : ∀ᵐ x ∂(volume.restrict s), differentiable_within_at ℝ f s x
h.has_locally_bounded_variation_on.ae_differentiable_within_at hs
lemma
lipschitz_on_with.ae_differentiable_within_at
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_within_at", "lipschitz_on_with", "measurable_set" ]
A real function into a finite dimensional real vector space which is Lipschitz on a set is differentiable almost everywhere in this set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_with.ae_differentiable_at {C : ℝ≥0} {f : ℝ → V} (h : lipschitz_with C f) : ∀ᵐ x, differentiable_at ℝ f x
(h.has_locally_bounded_variation_on univ).ae_differentiable_at
lemma
lipschitz_with.ae_differentiable_at
analysis
src/analysis/bounded_variation.lean
[ "analysis.calculus.deriv.add", "analysis.calculus.fderiv.equiv", "analysis.calculus.fderiv.prod", "analysis.calculus.monotone", "data.set.function", "algebra.group.basic", "tactic.wlog" ]
[ "differentiable_at", "lipschitz_with" ]
A real Lipschitz function into a finite dimensional real vector space is differentiable almost everywhere.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_constant_speed_on_with
∀ ⦃x⦄ (hx : x ∈ s) ⦃y⦄ (hy : y ∈ s), evariation_on f (s ∩ Icc x y) = ennreal.of_real (l * (y - x))
def
has_constant_speed_on_with
analysis
src/analysis/constant_speed.lean
[ "data.set.function", "analysis.bounded_variation", "tactic.swap_var" ]
[ "ennreal.of_real", "evariation_on" ]
`f` has constant speed `l` on `s` if the variation of `f` on `s ∩ Icc x y` is equal to `l * (y - x)` for any `x y` in `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83