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diam_le {d : ℝ≥0∞} (h : ∀ (x ∈ s) (y ∈ s), edist x y ≤ d) : diam s ≤ d
diam_le_iff.2 h
lemma
emetric.diam_le
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
If the distance between any two points in a set is bounded by some constant, this constant bounds the diameter.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_subsingleton (hs : s.subsingleton) : diam s = 0
nonpos_iff_eq_zero.1 $ diam_le $ λ x hx y hy, (hs hx hy).symm ▸ edist_self y ▸ le_rfl
lemma
emetric.diam_subsingleton
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "le_rfl" ]
The diameter of a subsingleton vanishes.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_Union_mem_option {ι : Type*} (o : option ι) (s : ι → set α) : diam (⋃ i ∈ o, s i) = ⨆ i ∈ o, diam (s i)
by cases o; simp
lemma
emetric.diam_Union_mem_option
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_insert : diam (insert x s) = max (⨆ y ∈ s, edist x y) (diam s)
eq_of_forall_ge_iff $ λ d, by simp only [diam_le_iff, ball_insert_iff, edist_self, edist_comm x, max_le_iff, supr_le_iff, zero_le, true_and, forall_and_distrib, and_self, ← and_assoc]
lemma
emetric.diam_insert
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "eq_of_forall_ge_iff", "forall_and_distrib", "max_le_iff", "supr_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_pair : diam ({x, y} : set α) = edist x y
by simp only [supr_singleton, diam_insert, diam_singleton, ennreal.max_zero_right]
lemma
emetric.diam_pair
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "ennreal.max_zero_right", "supr_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_triple : diam ({x, y, z} : set α) = max (max (edist x y) (edist x z)) (edist y z)
by simp only [diam_insert, supr_insert, supr_singleton, diam_singleton, ennreal.max_zero_right, ennreal.sup_eq_max]
lemma
emetric.diam_triple
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "ennreal.max_zero_right", "ennreal.sup_eq_max", "supr_insert", "supr_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_mono {s t : set α} (h : s ⊆ t) : diam s ≤ diam t
diam_le $ λ x hx y hy, edist_le_diam_of_mem (h hx) (h hy)
lemma
emetric.diam_mono
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
The diameter is monotonous with respect to inclusion
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_union {t : set α} (xs : x ∈ s) (yt : y ∈ t) : diam (s ∪ t) ≤ diam s + edist x y + diam t
begin have A : ∀a ∈ s, ∀b ∈ t, edist a b ≤ diam s + edist x y + diam t := λa ha b hb, calc edist a b ≤ edist a x + edist x y + edist y b : edist_triangle4 _ _ _ _ ... ≤ diam s + edist x y + diam t : add_le_add (add_le_add (edist_le_diam_of_mem ha xs) le_rfl) (edist_le_diam_of_mem yt hb), refine diam_l...
lemma
emetric.diam_union
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "edist_triangle4", "le_rfl" ]
The diameter of a union is controlled by the diameter of the sets, and the edistance between two points in the sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_union' {t : set α} (h : (s ∩ t).nonempty) : diam (s ∪ t) ≤ diam s + diam t
let ⟨x, ⟨xs, xt⟩⟩ := h in by simpa using diam_union xs xt
lemma
emetric.diam_union'
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_closed_ball {r : ℝ≥0∞} : diam (closed_ball x r) ≤ 2 * r
diam_le $ λa ha b hb, calc edist a b ≤ edist a x + edist b x : edist_triangle_right _ _ _ ... ≤ r + r : add_le_add ha hb ... = 2 * r : (two_mul r).symm
lemma
emetric.diam_closed_ball
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "edist_triangle_right", "two_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_ball {r : ℝ≥0∞} : diam (ball x r) ≤ 2 * r
le_trans (diam_mono ball_subset_closed_ball) diam_closed_ball
lemma
emetric.diam_ball
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_pi_le_of_le {π : β → Type*} [fintype β] [∀ b, pseudo_emetric_space (π b)] {s : Π (b : β), set (π b)} {c : ℝ≥0∞} (h : ∀ b, diam (s b) ≤ c) : diam (set.pi univ s) ≤ c
begin apply diam_le (λ x hx y hy, edist_pi_le_iff.mpr _), rw [mem_univ_pi] at hx hy, exact λ b, diam_le_iff.1 (h b) (x b) (hx b) (y b) (hy b), end
lemma
emetric.diam_pi_le_of_le
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "fintype", "pseudo_emetric_space", "set.pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric_space (α : Type u) extends pseudo_emetric_space α : Type u
(eq_of_edist_eq_zero : ∀ {x y : α}, edist x y = 0 → x = y)
class
emetric_space
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "pseudo_emetric_space" ]
We now define `emetric_space`, extending `pseudo_emetric_space`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_eq_zero {x y : γ} : edist x y = 0 ↔ x = y
iff.intro eq_of_edist_eq_zero (assume : x = y, this ▸ edist_self _)
theorem
edist_eq_zero
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
Characterize the equality of points by the vanishing of their extended distance
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_eq_edist {x y : γ} : 0 = edist x y ↔ x = y
iff.intro (assume h, eq_of_edist_eq_zero (h.symm)) (assume : x = y, this ▸ (edist_self _).symm)
theorem
zero_eq_edist
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_le_zero {x y : γ} : (edist x y ≤ 0) ↔ x = y
nonpos_iff_eq_zero.trans edist_eq_zero
theorem
edist_le_zero
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "edist_eq_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_pos {x y : γ} : 0 < edist x y ↔ x ≠ y
by simp [← not_le]
theorem
edist_pos
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_forall_edist_le {x y : γ} (h : ∀ε > 0, edist x y ≤ ε) : x = y
eq_of_edist_eq_zero (eq_of_le_of_forall_le_of_dense bot_le h)
theorem
eq_of_forall_edist_le
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "bot_le", "eq_of_le_of_forall_le_of_dense" ]
Two points coincide if their distance is `< ε` for all positive ε
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_separated : separated_space γ
separated_def.2 $ λ x y h, eq_of_forall_edist_le $ λ ε ε0, le_of_lt (h _ (edist_mem_uniformity ε0))
instance
to_separated
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "edist_mem_uniformity", "eq_of_forall_edist_le", "separated_space" ]
An emetric space is separated
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric.uniform_embedding_iff' [emetric_space β] {f : γ → β} : uniform_embedding f ↔ (∀ ε > 0, ∃ δ > 0, ∀ {a b : γ}, edist a b < δ → edist (f a) (f b) < ε) ∧ (∀ δ > 0, ∃ ε > 0, ∀ {a b : γ}, edist (f a) (f b) < ε → edist a b < δ)
begin simp only [uniform_embedding_iff_uniform_inducing, uniformity_basis_edist.uniform_inducing_iff uniformity_basis_edist, exists_prop], refl end
theorem
emetric.uniform_embedding_iff'
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "exists_prop", "uniform_embedding", "uniform_embedding_iff_uniform_inducing", "uniformity_basis_edist" ]
A map between emetric spaces is a uniform embedding if and only if the edistance between `f x` and `f y` is controlled in terms of the distance between `x` and `y` and conversely.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric_space.of_t0_pseudo_emetric_space (α : Type*) [pseudo_emetric_space α] [t0_space α] : emetric_space α
{ eq_of_edist_eq_zero := λ x y hdist, (emetric.inseparable_iff.2 hdist).eq, ..‹pseudo_emetric_space α› }
def
emetric_space.of_t0_pseudo_emetric_space
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "pseudo_emetric_space", "t0_space" ]
If a `pseudo_emetric_space` is a T₀ space, then it is an `emetric_space`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric_space.replace_uniformity {γ} [U : uniform_space γ] (m : emetric_space γ) (H : 𝓤[U] = 𝓤[pseudo_emetric_space.to_uniform_space]) : emetric_space γ
{ edist := @edist _ m.to_has_edist, edist_self := edist_self, eq_of_edist_eq_zero := @eq_of_edist_eq_zero _ _, edist_comm := edist_comm, edist_triangle := edist_triangle, to_uniform_space := U, uniformity_edist := H.trans (@pseudo_emetric_space.uniformity_edist γ _...
def
emetric_space.replace_uniformity
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "uniform_space", "uniformity_edist" ]
Auxiliary function to replace the uniformity on an emetric space with a uniformity which is equal to the original one, but maybe not defeq. This is useful if one wants to construct an emetric space with a specified uniformity. See Note [forgetful inheritance] explaining why having definitionally the right uniformity is...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric_space.induced {γ β} (f : γ → β) (hf : function.injective f) (m : emetric_space β) : emetric_space γ
{ edist := λ x y, edist (f x) (f y), edist_self := λ x, edist_self _, eq_of_edist_eq_zero := λ x y h, hf (edist_eq_zero.1 h), edist_comm := λ x y, edist_comm _ _, edist_triangle := λ x y z, edist_triangle _ _ _, to_uniform_space := uniform_space.comap f m.to_uniform_spa...
def
emetric_space.induced
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "uniform_space.comap", "uniformity_edist" ]
The extended metric induced by an injective function taking values in a emetric space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod.emetric_space_max [emetric_space β] : emetric_space (γ × β)
{ eq_of_edist_eq_zero := λ x y h, begin cases max_le_iff.1 (le_of_eq h) with h₁ h₂, have A : x.fst = y.fst := edist_le_zero.1 h₁, have B : x.snd = y.snd := edist_le_zero.1 h₂, exact prod.ext_iff.2 ⟨A, B⟩ end, ..prod.pseudo_emetric_space_max }
instance
prod.emetric_space_max
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "prod.pseudo_emetric_space_max" ]
The product of two emetric spaces, with the max distance, is an extended metric spaces. We make sure that the uniform structure thus constructed is the one corresponding to the product of uniform spaces, to avoid diamond problems.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniformity_edist : 𝓤 γ = ⨅ ε>0, 𝓟 {p:γ×γ | edist p.1 p.2 < ε}
pseudo_emetric_space.uniformity_edist
theorem
uniformity_edist
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
Reformulation of the uniform structure in terms of the extended distance
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
emetric_space_pi [∀b, emetric_space (π b)] : emetric_space (Πb, π b)
{ eq_of_edist_eq_zero := assume f g eq0, begin have eq1 : sup univ (λ (b : β), edist (f b) (g b)) ≤ 0 := le_of_eq eq0, simp only [finset.sup_le_iff] at eq1, exact (funext $ assume b, edist_le_zero.1 $ eq1 b $ mem_univ b), end, ..pseudo_emetric_space_pi }
instance
emetric_space_pi
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "emetric_space", "finset.sup_le_iff", "pseudo_emetric_space_pi" ]
The product of a finite number of emetric spaces, with the max distance, is still an emetric space. This construction would also work for infinite products, but it would not give rise to the product topology. Hence, we only formalize it in the good situation of finitely many spaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
countable_closure_of_compact {s : set γ} (hs : is_compact s) : ∃ t ⊆ s, (t.countable ∧ s = closure t)
begin rcases subset_countable_closure_of_compact hs with ⟨t, hts, htc, hsub⟩, exact ⟨t, hts, htc, subset.antisymm hsub (closure_minimal hts hs.is_closed)⟩ end
lemma
emetric.countable_closure_of_compact
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "closure", "closure_minimal", "is_compact" ]
A compact set in an emetric space is separable, i.e., it is the closure of a countable set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_eq_zero_iff : diam s = 0 ↔ s.subsingleton
⟨λ h x hx y hy, edist_le_zero.1 $ h ▸ edist_le_diam_of_mem hx hy, diam_subsingleton⟩
lemma
emetric.diam_eq_zero_iff
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diam_pos_iff : 0 < diam s ↔ ∃ (x ∈ s) (y ∈ s), x ≠ y
by simp only [pos_iff_ne_zero, ne.def, diam_eq_zero_iff, set.subsingleton, not_forall]
lemma
emetric.diam_pos_iff
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "not_forall", "set.subsingleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_space.separation_quotient.edist_mk [pseudo_emetric_space X] (x y : X) : @edist (uniform_space.separation_quotient X) _ (quot.mk _ x) (quot.mk _ y) = edist x y
rfl
theorem
uniform_space.separation_quotient.edist_mk
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "pseudo_emetric_space", "uniform_space.separation_quotient" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_of_mul (a b : X) : edist (of_mul a) (of_mul b) = edist a b
rfl
lemma
edist_of_mul
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_of_add (a b : X) : edist (of_add a) (of_add b) = edist a b
rfl
lemma
edist_of_add
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_to_mul (a b : additive X) : edist (to_mul a) (to_mul b) = edist a b
rfl
lemma
edist_to_mul
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "additive" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_to_add (a b : multiplicative X) : edist (to_add a) (to_add b) = edist a b
rfl
lemma
edist_to_add
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[ "multiplicative" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_to_dual (a b : X) : edist (to_dual a) (to_dual b) = edist a b
rfl
lemma
edist_to_dual
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
edist_of_dual (a b : Xᵒᵈ) : edist (of_dual a) (of_dual b) = edist a b
rfl
lemma
edist_of_dual
topology.metric_space
src/topology/metric_space/emetric_space.lean
[ "data.nat.interval", "data.real.ennreal", "topology.uniform_space.pi", "topology.uniform_space.uniform_convergence", "topology.uniform_space.uniform_embedding" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equicontinuous_at_iff_right {ι : Type*} [topological_space β] {F : ι → β → α} {x₀ : β} : equicontinuous_at F x₀ ↔ ∀ ε > 0, ∀ᶠ x in 𝓝 x₀, ∀ i, dist (F i x₀) (F i x) < ε
uniformity_basis_dist.equicontinuous_at_iff_right
lemma
metric.equicontinuous_at_iff_right
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "equicontinuous_at", "topological_space" ]
Characterization of equicontinuity for families of functions taking values in a (pseudo) metric space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equicontinuous_at_iff {ι : Type*} [pseudo_metric_space β] {F : ι → β → α} {x₀ : β} : equicontinuous_at F x₀ ↔ ∀ ε > 0, ∃ δ > 0, ∀ x, dist x x₀ < δ → ∀ i, dist (F i x₀) (F i x) < ε
nhds_basis_ball.equicontinuous_at_iff uniformity_basis_dist
lemma
metric.equicontinuous_at_iff
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "equicontinuous_at", "pseudo_metric_space" ]
Characterization of equicontinuity for families of functions between (pseudo) metric spaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equicontinuous_at_iff_pair {ι : Type*} [topological_space β] {F : ι → β → α} {x₀ : β} : equicontinuous_at F x₀ ↔ ∀ ε > 0, ∃ U ∈ 𝓝 x₀, ∀ (x x' ∈ U), ∀ i, dist (F i x) (F i x') < ε
begin rw equicontinuous_at_iff_pair, split; intros H, { intros ε hε, refine exists_imp_exists (λ V, exists_imp_exists $ λ hV h, _) (H _ (dist_mem_uniformity hε)), exact λ x hx x' hx', h _ hx _ hx' }, { intros U hU, rcases mem_uniformity_dist.mp hU with ⟨ε, hε, hεU⟩, refine exists_imp_exists (λ V...
lemma
metric.equicontinuous_at_iff_pair
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "equicontinuous_at", "equicontinuous_at_iff_pair", "topological_space" ]
Reformulation of `equicontinuous_at_iff_pair` for families of functions taking values in a (pseudo) metric space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_equicontinuous_iff_right {ι : Type*} [uniform_space β] {F : ι → β → α} : uniform_equicontinuous F ↔ ∀ ε > 0, ∀ᶠ (xy : β × β) in 𝓤 β, ∀ i, dist (F i xy.1) (F i xy.2) < ε
uniformity_basis_dist.uniform_equicontinuous_iff_right
lemma
metric.uniform_equicontinuous_iff_right
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "uniform_equicontinuous", "uniform_space" ]
Characterization of uniform equicontinuity for families of functions taking values in a (pseudo) metric space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_equicontinuous_iff {ι : Type*} [pseudo_metric_space β] {F : ι → β → α} : uniform_equicontinuous F ↔ ∀ ε > 0, ∃ δ > 0, ∀ x y, dist x y < δ → ∀ i, dist (F i x) (F i y) < ε
uniformity_basis_dist.uniform_equicontinuous_iff uniformity_basis_dist
lemma
metric.uniform_equicontinuous_iff
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "pseudo_metric_space", "uniform_equicontinuous" ]
Characterization of uniform equicontinuity for families of functions between (pseudo) metric spaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equicontinuous_at_of_continuity_modulus {ι : Type*} [topological_space β] {x₀ : β} (b : β → ℝ) (b_lim : tendsto b (𝓝 x₀) (𝓝 0)) (F : ι → β → α) (H : ∀ᶠ x in 𝓝 x₀, ∀ i, dist (F i x₀) (F i x) ≤ b x) : equicontinuous_at F x₀
begin rw metric.equicontinuous_at_iff_right, intros ε ε0, filter_upwards [b_lim (Iio_mem_nhds ε0), H] using λ x hx₁ hx₂ i, (hx₂ i).trans_lt hx₁ end
lemma
metric.equicontinuous_at_of_continuity_modulus
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "Iio_mem_nhds", "equicontinuous_at", "metric.equicontinuous_at_iff_right", "topological_space" ]
For a family of functions to a (pseudo) metric spaces, a convenient way to prove equicontinuity at a point is to show that all of the functions share a common *local* continuity modulus.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_equicontinuous_of_continuity_modulus {ι : Type*} [pseudo_metric_space β] (b : ℝ → ℝ) (b_lim : tendsto b (𝓝 0) (𝓝 0)) (F : ι → β → α) (H : ∀ (x y : β) i, dist (F i x) (F i y) ≤ b (dist x y)) : uniform_equicontinuous F
begin rw metric.uniform_equicontinuous_iff, intros ε ε0, rcases tendsto_nhds_nhds.1 b_lim ε ε0 with ⟨δ, δ0, hδ⟩, refine ⟨δ, δ0, λ x y hxy i, _⟩, calc dist (F i x) (F i y) ≤ b (dist x y) : H x y i ... ≤ |b (dist x y)| : le_abs_self _ ... = dist (b (dist x y)) 0 : by simp [real.dist_eq] ... < ε ...
lemma
metric.uniform_equicontinuous_of_continuity_modulus
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "abs_dist", "le_abs_self", "metric.uniform_equicontinuous_iff", "pseudo_metric_space", "real.dist_eq", "tsub_zero", "uniform_equicontinuous" ]
For a family of functions between (pseudo) metric spaces, a convenient way to prove uniform equicontinuity is to show that all of the functions share a common *global* continuity modulus.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
equicontinuous_of_continuity_modulus {ι : Type*} [pseudo_metric_space β] (b : ℝ → ℝ) (b_lim : tendsto b (𝓝 0) (𝓝 0)) (F : ι → β → α) (H : ∀ (x y : β) i, dist (F i x) (F i y) ≤ b (dist x y)) : equicontinuous F
(uniform_equicontinuous_of_continuity_modulus b b_lim F H).equicontinuous
lemma
metric.equicontinuous_of_continuity_modulus
topology.metric_space
src/topology/metric_space/equicontinuity.lean
[ "topology.metric_space.basic", "topology.uniform_space.equicontinuity" ]
[ "equicontinuous", "pseudo_metric_space" ]
For a family of functions between (pseudo) metric spaces, a convenient way to prove equicontinuity is to show that all of the functions share a common *global* continuity modulus.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_dist (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) : X ⊕ Y → X ⊕ Y → ℝ
| (inl x) (inl y) := dist x y | (inr x) (inr y) := dist x y | (inl x) (inr y) := (⨅ p, dist x (Φ p) + dist y (Ψ p)) + ε | (inr x) (inl y) := (⨅ p, dist y (Φ p) + dist x (Ψ p)) + ε
def
metric.glue_dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
Define a predistance on `X ⊕ Y`, for which `Φ p` and `Ψ p` are at distance `ε`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_dist_self (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) : ∀ x, glue_dist Φ Ψ ε x x = 0
| (inl x) := dist_self _ | (inr x) := dist_self _
lemma
metric.glue_dist_self
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_self" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_dist_glued_points [nonempty Z] (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) (p : Z) : glue_dist Φ Ψ ε (inl (Φ p)) (inr (Ψ p)) = ε
begin have : (⨅ q, dist (Φ p) (Φ q) + dist (Ψ p) (Ψ q)) = 0, { have A : ∀ q, 0 ≤ dist (Φ p) (Φ q) + dist (Ψ p) (Ψ q) := λq, by rw ← add_zero (0 : ℝ); exact add_le_add dist_nonneg dist_nonneg, refine le_antisymm _ (le_cinfi A), have : 0 = dist (Φ p) (Φ p) + dist (Ψ p) (Ψ p), by simp, rw this, e...
lemma
metric.glue_dist_glued_points
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "cinfi_le", "dist_nonneg", "le_cinfi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_dist_comm (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) : ∀ x y, glue_dist Φ Ψ ε x y = glue_dist Φ Ψ ε y x
| (inl x) (inl y) := dist_comm _ _ | (inr x) (inr y) := dist_comm _ _ | (inl x) (inr y) := rfl | (inr x) (inl y) := rfl
lemma
metric.glue_dist_comm
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_dist_triangle (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) (H : ∀ p q, |dist (Φ p) (Φ q) - dist (Ψ p) (Ψ q)| ≤ 2 * ε) : ∀ x y z, glue_dist Φ Ψ ε x z ≤ glue_dist Φ Ψ ε x y + glue_dist Φ Ψ ε y z
| (inl x) (inl y) (inl z) := dist_triangle _ _ _ | (inr x) (inr y) (inr z) := dist_triangle _ _ _ | (inr x) (inl y) (inl z) := begin have B : ∀ a b, bdd_below (range (λ (p : Z), dist a (Φ p) + dist b (Ψ p))) := λa b, ⟨0, forall_range_iff.2 (λp, add_nonneg dist_nonneg dist_nonneg)⟩, unfold glue_dist, h...
lemma
metric.glue_dist_triangle
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "bdd_below", "cinfi_mono", "continuous_at_const", "continuous_at_id", "dist_comm", "dist_nonneg", "dist_triangle", "dist_triangle4", "dist_triangle_left", "exists_lt_of_cinfi_lt", "infi", "le_abs_self", "le_rfl", "monotone.map_cinfi_of_continuous_at", "neg_le_abs_self", "ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_eq_of_dist_eq_zero (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) (ε0 : 0 < ε) : ∀ p q : X ⊕ Y, glue_dist Φ Ψ ε p q = 0 → p = q
| (inl x) (inl y) h := by rw eq_of_dist_eq_zero h | (inl x) (inr y) h := begin have : 0 ≤ (⨅ p, dist x (Φ p) + dist y (Ψ p)) := le_cinfi (λp, by simpa using add_le_add (@dist_nonneg _ _ x _) (@dist_nonneg _ _ y _)), have : 0 + ε ≤ glue_dist Φ Ψ ε (inl x) (inr y) := add_le_add this (le_refl ε), exfalso...
lemma
metric.glue_eq_of_dist_eq_zero
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_nonneg", "eq_of_dist_eq_zero", "le_cinfi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_metric_approx (Φ : Z → X) (Ψ : Z → Y) (ε : ℝ) (ε0 : 0 < ε) (H : ∀ p q, |dist (Φ p) (Φ q) - dist (Ψ p) (Ψ q)| ≤ 2 * ε) : metric_space (X ⊕ Y)
{ dist := glue_dist Φ Ψ ε, dist_self := glue_dist_self Φ Ψ ε, dist_comm := glue_dist_comm Φ Ψ ε, dist_triangle := glue_dist_triangle Φ Ψ ε H, eq_of_dist_eq_zero := glue_eq_of_dist_eq_zero Φ Ψ ε ε0 }
def
metric.glue_metric_approx
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "dist_self", "dist_triangle", "eq_of_dist_eq_zero", "metric_space" ]
Given two maps `Φ` and `Ψ` intro metric spaces `X` and `Y` such that the distances between `Φ p` and `Φ q`, and between `Ψ p` and `Ψ q`, coincide up to `2 ε` where `ε > 0`, one can almost glue the two spaces `X` and `Y` along the images of `Φ` and `Ψ`, so that `Φ p` and `Ψ p` are at distance `ε`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.dist : X ⊕ Y → X ⊕ Y → ℝ
| (inl a) (inl a') := dist a a' | (inr b) (inr b') := dist b b' | (inl a) (inr b) := dist a (nonempty.some ⟨a⟩) + 1 + dist (nonempty.some ⟨b⟩) b | (inr b) (inl a) := dist b (nonempty.some ⟨b⟩) + 1 + dist (nonempty.some ⟨a⟩) a
def
metric.sum.dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "nonempty.some" ]
Distance on a disjoint union. There are many (noncanonical) ways to put a distance compatible with each factor. If the two spaces are bounded, one can say for instance that each point in the first is at distance `diam X + diam Y + 1` of each point in the second. Instead, we choose a construction that works for unbounde...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.dist_eq_glue_dist {p q : X ⊕ Y} (x : X) (y : Y) : sum.dist p q = glue_dist (λ _ : unit, nonempty.some ⟨x⟩) (λ _ : unit, nonempty.some ⟨y⟩) 1 p q
by cases p; cases q; refl <|> simp [sum.dist, glue_dist, dist_comm, add_comm, add_left_comm]
lemma
metric.sum.dist_eq_glue_dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "nonempty.some" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.dist_comm (x y : X ⊕ Y) : sum.dist x y = sum.dist y x
by cases x; cases y; simp only [sum.dist, dist_comm, add_comm, add_left_comm]
lemma
metric.sum.dist_comm
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.one_dist_le {x : X} {y : Y} : 1 ≤ sum.dist (inl x) (inr y)
le_trans (le_add_of_nonneg_right dist_nonneg) $ add_le_add_right (le_add_of_nonneg_left dist_nonneg) _
lemma
metric.sum.one_dist_le
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_nonneg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.one_dist_le' {x : X} {y : Y} : 1 ≤ sum.dist (inr y) (inl x)
by rw sum.dist_comm; exact sum.one_dist_le
lemma
metric.sum.one_dist_le'
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.mem_uniformity (s : set ((X ⊕ Y) × (X ⊕ Y))) : s ∈ 𝓤 (X ⊕ Y) ↔ ∃ ε > 0, ∀ a b, sum.dist a b < ε → (a, b) ∈ s
begin split, { rintro ⟨hsX, hsY⟩, rcases mem_uniformity_dist.1 hsX with ⟨εX, εX0, hX⟩, rcases mem_uniformity_dist.1 hsY with ⟨εY, εY0, hY⟩, refine ⟨min (min εX εY) 1, lt_min (lt_min εX0 εY0) zero_lt_one, _⟩, rintro (a|a) (b|b) h, { exact hX (lt_of_lt_of_le h (le_trans (min_le_left _ _) (min_le_l...
lemma
metric.sum.mem_uniformity
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "filter.mem_map", "filter.mem_sets", "not_le_of_lt", "zero_lt_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
metric_space_sum : metric_space (X ⊕ Y)
{ dist := sum.dist, dist_self := λx, by cases x; simp only [sum.dist, dist_self], dist_comm := sum.dist_comm, dist_triangle := λ p q r, begin cases p; cases q; cases r, { exact dist_triangle _ _ _ }, { simp only [dist, sum.dist_eq_glue_dist p r], exact glue...
def
metric.metric_space_sum
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "dist_eq_zero", "dist_self", "dist_triangle", "eq_of_dist_eq_zero", "imp_self", "metric_space", "sum.uniform_space", "uniformity_dist_of_mem_uniformity", "zero_lt_one" ]
The distance on the disjoint union indeed defines a metric space. All the distance properties follow from our choice of the distance. The harder work is to show that the uniform structure defined by the distance coincides with the disjoint union uniform structure.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum.dist_eq {x y : X ⊕ Y} : dist x y = sum.dist x y
rfl
lemma
metric.sum.dist_eq
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_inl : isometry (sum.inl : X → (X ⊕ Y))
isometry.of_dist_eq $ λ x y, rfl
lemma
metric.isometry_inl
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
The left injection of a space in a disjoint union is an isometry
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_inr : isometry (sum.inr : Y → (X ⊕ Y))
isometry.of_dist_eq $ λ x y, rfl
lemma
metric.isometry_inr
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
The right injection of a space in a disjoint union is an isometry
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist : (Σ i, E i) → (Σ i, E i) → ℝ
| ⟨i, x⟩ ⟨j, y⟩ := if h : i = j then by { have : E j = E i, by rw h, exact has_dist.dist x (cast this y) } else has_dist.dist x (nonempty.some ⟨x⟩) + 1 + has_dist.dist (nonempty.some ⟨y⟩) y
def
metric.sigma.dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "nonempty.some" ]
Distance on a disjoint union. There are many (noncanonical) ways to put a distance compatible with each factor. We choose a construction that works for unbounded spaces, but requires basepoints, chosen arbitrarily. We embed isometrically each factor, set the basepoints at distance 1, arbitrarily, and say that the dista...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_dist : has_dist (Σ i, E i)
⟨sigma.dist⟩
def
metric.sigma.has_dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "has_dist" ]
A `has_dist` instance on the disjoint union `Σ i, E i`. We embed isometrically each factor, set the basepoints at distance 1, arbitrarily, and say that the distance from `a` to `b` is the sum of the distances of `a` and `b` to their respective basepoints, plus the distance 1 between the basepoints. Since there is an ar...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_same (i : ι) (x : E i) (y : E i) : dist (⟨i, x⟩ : Σ j, E j) ⟨i, y⟩ = dist x y
by simp [has_dist.dist, sigma.dist]
lemma
metric.sigma.dist_same
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_ne {i j : ι} (h : i ≠ j) (x : E i) (y : E j) : dist (⟨i, x⟩ : Σ k, E k) ⟨j, y⟩ = dist x (nonempty.some ⟨x⟩) + 1 + dist (nonempty.some ⟨y⟩) y
by simp [has_dist.dist, sigma.dist, h]
lemma
metric.sigma.dist_ne
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "nonempty.some" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_le_dist_of_ne {i j : ι} (h : i ≠ j) (x : E i) (y : E j) : 1 ≤ dist (⟨i, x⟩ : Σ k, E k) ⟨j, y⟩
begin rw sigma.dist_ne h x y, linarith [@dist_nonneg _ _ x (nonempty.some ⟨x⟩), @dist_nonneg _ _ (nonempty.some ⟨y⟩) y] end
lemma
metric.sigma.one_le_dist_of_ne
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_nonneg", "nonempty.some" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fst_eq_of_dist_lt_one (x y : Σ i, E i) (h : dist x y < 1) : x.1 = y.1
begin cases x, cases y, contrapose! h, apply one_le_dist_of_ne h, end
lemma
metric.sigma.fst_eq_of_dist_lt_one
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_triangle (x y z : Σ i, E i) : dist x z ≤ dist x y + dist y z
begin rcases x with ⟨i, x⟩, rcases y with ⟨j, y⟩, rcases z with ⟨k, z⟩, rcases eq_or_ne i k with rfl|hik, { rcases eq_or_ne i j with rfl|hij, { simpa using dist_triangle x y z }, { simp only [hij, hij.symm, sigma.dist_same, sigma.dist_ne, ne.def, not_false_iff], calc dist x z ≤ dist x (nonempty.some...
lemma
metric.sigma.dist_triangle
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_nonneg", "dist_triangle", "eq_or_ne", "le_rfl", "nonempty.some", "zero_le_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_iff (s : set (Σ i, E i)) : is_open s ↔ ∀ x ∈ s, ∃ ε > 0, ∀ y, dist x y < ε → y ∈ s
begin split, { rintros hs ⟨i, x⟩ hx, obtain ⟨ε, εpos, hε⟩ : ∃ (ε : ℝ) (H : ε > 0), ball x ε ⊆ sigma.mk i ⁻¹' s := metric.is_open_iff.1 (is_open_sigma_iff.1 hs i) x hx, refine ⟨min ε 1, lt_min εpos zero_lt_one, _⟩, rintros ⟨j, y⟩ hy, rcases eq_or_ne i j with rfl|hij, { simp only [sigma.dist...
lemma
metric.sigma.is_open_iff
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "eq_or_ne", "is_open", "lt_min_iff", "zero_lt_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
metric_space : metric_space (Σ i, E i)
begin refine metric_space.of_dist_topology sigma.dist _ _ sigma.dist_triangle sigma.is_open_iff _, { rintros ⟨i, x⟩, simp [sigma.dist] }, { rintros ⟨i, x⟩ ⟨j, y⟩, rcases eq_or_ne i j with rfl|h, { simp [sigma.dist, dist_comm] }, { simp only [sigma.dist, dist_comm, h, h.symm, not_false_iff, dif_neg...
def
metric.sigma.metric_space
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "eq_or_ne", "metric_space", "metric_space.of_dist_topology", "zero_lt_one" ]
A metric space structure on the disjoint union `Σ i, E i`. We embed isometrically each factor, set the basepoints at distance 1, arbitrarily, and say that the distance from `a` to `b` is the sum of the distances of `a` and `b` to their respective basepoints, plus the distance 1 between the basepoints. Since there is an...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_mk (i : ι) : isometry (sigma.mk i : E i → Σ k, E k)
isometry.of_dist_eq (λ x y, by simp)
lemma
metric.sigma.isometry_mk
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
The injection of a space in a disjoint union is an isometry
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complete_space [∀ i, complete_space (E i)] : complete_space (Σ i, E i)
begin set s : ι → set (Σ i, E i) := λ i, (sigma.fst ⁻¹' {i}), set U := {p : (Σ k, E k) × (Σ k, E k) | dist p.1 p.2 < 1}, have hc : ∀ i, is_complete (s i), { intro i, simp only [s, ← range_sigma_mk], exact (isometry_mk i).uniform_inducing.is_complete_range }, have hd : ∀ i j (x ∈ s i) (y ∈ s j), (x, y)...
lemma
metric.sigma.complete_space
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "complete_space", "complete_space_of_is_complete_univ", "is_complete", "is_complete_Union_separated", "uniform_inducing.is_complete_range", "zero_lt_one" ]
A disjoint union of complete metric spaces is complete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_premetric (hΦ : isometry Φ) (hΨ : isometry Ψ) : pseudo_metric_space (X ⊕ Y)
{ dist := glue_dist Φ Ψ 0, dist_self := glue_dist_self Φ Ψ 0, dist_comm := glue_dist_comm Φ Ψ 0, dist_triangle := glue_dist_triangle Φ Ψ 0 $ λp q, by rw [hΦ.dist_eq, hΨ.dist_eq]; simp }
def
metric.glue_premetric
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "dist_self", "dist_triangle", "isometry", "pseudo_metric_space" ]
Given two isometric embeddings `Φ : Z → X` and `Ψ : Z → Y`, we define a pseudo metric space structure on `X ⊕ Y` by declaring that `Φ x` and `Ψ x` are at distance `0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_space (hΦ : isometry Φ) (hΨ : isometry Ψ) : Type*
@uniform_space.separation_quotient _ (glue_premetric hΦ hΨ).to_uniform_space
def
metric.glue_space
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "uniform_space.separation_quotient" ]
Given two isometric embeddings `Φ : Z → X` and `Ψ : Z → Y`, we define a space `glue_space hΦ hΨ` by identifying in `X ⊕ Y` the points `Φ x` and `Ψ x`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_glue_l (hΦ : isometry Φ) (hΨ : isometry Ψ) (x : X) : glue_space hΦ hΨ
quotient.mk' (inl x)
def
metric.to_glue_l
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "quotient.mk'" ]
The canonical map from `X` to the space obtained by gluing isometric subsets in `X` and `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_glue_r (hΦ : isometry Φ) (hΨ : isometry Ψ) (y : Y) : glue_space hΦ hΨ
quotient.mk' (inr y)
def
metric.to_glue_r
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "quotient.mk'" ]
The canonical map from `Y` to the space obtained by gluing isometric subsets in `X` and `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_left (hΦ : isometry Φ) (hΨ : isometry Ψ) [inhabited X] : inhabited (glue_space hΦ hΨ)
⟨to_glue_l _ _ default⟩
instance
metric.inhabited_left
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_right (hΦ : isometry Φ) (hΨ : isometry Ψ) [inhabited Y] : inhabited (glue_space hΦ hΨ)
⟨to_glue_r _ _ default⟩
instance
metric.inhabited_right
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_glue_commute (hΦ : isometry Φ) (hΨ : isometry Ψ) : (to_glue_l hΦ hΨ) ∘ Φ = (to_glue_r hΦ hΨ) ∘ Ψ
begin letI i : pseudo_metric_space (X ⊕ Y) := glue_premetric hΦ hΨ, letI := i.to_uniform_space, funext, simp only [comp, to_glue_l, to_glue_r], refine uniform_space.separation_quotient.mk_eq_mk.2 (metric.inseparable_iff.2 _), exact glue_dist_glued_points Φ Ψ 0 x end
lemma
metric.to_glue_commute
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "pseudo_metric_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_glue_l_isometry (hΦ : isometry Φ) (hΨ : isometry Ψ) : isometry (to_glue_l hΦ hΨ)
isometry.of_dist_eq $ λ_ _, rfl
lemma
metric.to_glue_l_isometry
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_glue_r_isometry (hΦ : isometry Φ) (hΨ : isometry Ψ) : isometry (to_glue_r hΦ hΨ)
isometry.of_dist_eq $ λ_ _, rfl
lemma
metric.to_glue_r_isometry
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inductive_limit_dist (f : Π n, X n → X (n+1)) (x y : Σ n, X n) : ℝ
dist (le_rec_on (le_max_left x.1 y.1) f x.2 : X (max x.1 y.1)) (le_rec_on (le_max_right x.1 y.1) f y.2 : X (max x.1 y.1))
def
metric.inductive_limit_dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[]
Predistance on the disjoint union `Σ n, X n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inductive_limit_dist_eq_dist (I : ∀ n, isometry (f n)) (x y : Σ n, X n) (m : ℕ) : ∀ hx : x.1 ≤ m, ∀ hy : y.1 ≤ m, inductive_limit_dist f x y = dist (le_rec_on hx f x.2 : X m) (le_rec_on hy f y.2 : X m)
begin induction m with m hm, { assume hx hy, have A : max x.1 y.1 = 0, { rw [nonpos_iff_eq_zero.1 hx, nonpos_iff_eq_zero.1 hy], simp }, unfold inductive_limit_dist, congr; simp only [A] }, { assume hx hy, by_cases h : max x.1 y.1 = m.succ, { unfold inductive_limit_dist, congr; simp only ...
lemma
metric.inductive_limit_dist_eq_dist
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
The predistance on the disjoint union `Σ n, X n` can be computed in any `X k` for large enough `k`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inductive_premetric (I : ∀ n, isometry (f n)) : pseudo_metric_space (Σ n, X n)
{ dist := inductive_limit_dist f, dist_self := λx, by simp [dist, inductive_limit_dist], dist_comm := λx y, begin let m := max x.1 y.1, have hx : x.1 ≤ m := le_max_left _ _, have hy : y.1 ≤ m := le_max_right _ _, unfold dist, rw [inductive_limit_dist_eq_dist I x y m hx hy, induc...
def
metric.inductive_premetric
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_comm", "dist_self", "dist_triangle", "isometry", "pseudo_metric_space" ]
Premetric space structure on `Σ n, X n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inductive_limit (I : ∀ n, isometry (f n)) : Type*
@uniform_space.separation_quotient _ (inductive_premetric I).to_uniform_space
def
metric.inductive_limit
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "uniform_space.separation_quotient" ]
The type giving the inductive limit in a metric space context.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_inductive_limit (I : ∀ n, isometry (f n)) (n : ℕ) (x : X n) : metric.inductive_limit I
quotient.mk' (sigma.mk n x)
def
metric.to_inductive_limit
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry", "metric.inductive_limit", "quotient.mk'" ]
Mapping each `X n` to the inductive limit.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_inductive_limit_isometry (I : ∀ n, isometry (f n)) (n : ℕ) : isometry (to_inductive_limit I n)
isometry.of_dist_eq $ λ x y, begin change inductive_limit_dist f ⟨n, x⟩ ⟨n, y⟩ = dist x y, rw [inductive_limit_dist_eq_dist I ⟨n, x⟩ ⟨n, y⟩ n (le_refl n) (le_refl n), le_rec_on_self, le_rec_on_self] end
lemma
metric.to_inductive_limit_isometry
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "isometry" ]
The map `to_inductive_limit n` mapping `X n` to the inductive limit is an isometry.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_inductive_limit_commute (I : ∀ n, isometry (f n)) (n : ℕ) : (to_inductive_limit I n.succ) ∘ (f n) = to_inductive_limit I n
begin letI := inductive_premetric I, funext, simp only [comp, to_inductive_limit], refine uniform_space.separation_quotient.mk_eq_mk.2 (metric.inseparable_iff.2 _), show inductive_limit_dist f ⟨n.succ, f n x⟩ ⟨n, x⟩ = 0, { rw [inductive_limit_dist_eq_dist I ⟨n.succ, f n x⟩ ⟨n, x⟩ n.succ, le_rec_on_s...
lemma
metric.to_inductive_limit_commute
topology.metric_space
src/topology/metric_space/gluing.lean
[ "topology.metric_space.isometry" ]
[ "dist_self", "isometry", "le_rfl" ]
The maps `to_inductive_limit n` are compatible with the maps `f n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_rel : nonempty_compacts ℓ_infty_ℝ → nonempty_compacts ℓ_infty_ℝ → Prop
λ x y, nonempty (x ≃ᵢ y)
def
Gromov_Hausdorff.isometry_rel
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[]
Equivalence relation identifying two nonempty compact sets which are isometric
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_equivalence_isometry_rel : equivalence isometry_rel
⟨λ x, ⟨isometry_equiv.refl _⟩, λ x y ⟨e⟩, ⟨e.symm⟩, λ x y z ⟨e⟩ ⟨f⟩, ⟨e.trans f⟩⟩
lemma
Gromov_Hausdorff.is_equivalence_isometry_rel
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[]
This is indeed an equivalence relation
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_rel.setoid : setoid (nonempty_compacts ℓ_infty_ℝ)
setoid.mk isometry_rel is_equivalence_isometry_rel
instance
Gromov_Hausdorff.isometry_rel.setoid
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[]
setoid instance identifying two isometric nonempty compact subspaces of ℓ^∞(ℝ)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
GH_space : Type
quotient (isometry_rel.setoid)
definition
Gromov_Hausdorff.GH_space
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[]
The Gromov-Hausdorff space
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_GH_space (X : Type u) [metric_space X] [compact_space X] [nonempty X] : GH_space
⟦nonempty_compacts.Kuratowski_embedding X⟧
definition
Gromov_Hausdorff.to_GH_space
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "compact_space", "metric_space" ]
Map any nonempty compact type to `GH_space`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
GH_space.rep (p : GH_space) : Type
(quotient.out p : nonempty_compacts ℓ_infty_ℝ)
def
Gromov_Hausdorff.GH_space.rep
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "quotient.out" ]
A metric space representative of any abstract point in `GH_space`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_to_GH_space_iff {X : Type u} [metric_space X] [compact_space X] [nonempty X] {p : nonempty_compacts ℓ_infty_ℝ} : ⟦p⟧ = to_GH_space X ↔ ∃ Ψ : X → ℓ_infty_ℝ, isometry Ψ ∧ range Ψ = p
begin simp only [to_GH_space, quotient.eq], refine ⟨λ h, _, _⟩, { rcases setoid.symm h with ⟨e⟩, have f := (Kuratowski_embedding.isometry X).isometry_equiv_on_range.trans e, use [λ x, f x, isometry_subtype_coe.comp f.isometry], rw [range_comp, f.range_eq_univ, set.image_univ, subtype.range_coe], r...
lemma
Gromov_Hausdorff.eq_to_GH_space_iff
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "Kuratowski_embedding", "Kuratowski_embedding.isometry", "compact_space", "isometry", "metric_space", "nonempty_compacts.Kuratowski_embedding", "quotient.eq", "set.image_univ", "subtype.range_coe" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_to_GH_space {p : nonempty_compacts ℓ_infty_ℝ} : ⟦p⟧ = to_GH_space p
eq_to_GH_space_iff.2 ⟨λ x, x, isometry_subtype_coe, subtype.range_coe⟩
lemma
Gromov_Hausdorff.eq_to_GH_space
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "isometry_subtype_coe" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rep_GH_space_metric_space {p : GH_space} : metric_space p.rep
by apply_instance
instance
Gromov_Hausdorff.rep_GH_space_metric_space
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "metric_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rep_GH_space_compact_space {p : GH_space} : compact_space p.rep
by apply_instance
instance
Gromov_Hausdorff.rep_GH_space_compact_space
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rep_GH_space_nonempty {p : GH_space} : nonempty p.rep
by apply_instance
instance
Gromov_Hausdorff.rep_GH_space_nonempty
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
GH_space.to_GH_space_rep (p : GH_space) : to_GH_space p.rep = p
begin change to_GH_space (quot.out p : nonempty_compacts ℓ_infty_ℝ) = p, rw ← eq_to_GH_space, exact quot.out_eq p end
lemma
Gromov_Hausdorff.GH_space.to_GH_space_rep
topology.metric_space
src/topology/metric_space/gromov_hausdorff.lean
[ "set_theory.cardinal.basic", "topology.metric_space.closeds", "topology.metric_space.completion", "topology.metric_space.gromov_hausdorff_realized", "topology.metric_space.kuratowski" ]
[ "quot.out", "quot.out_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83