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dense_range.subset_closure_image_preimage_of_is_open (hf : dense_range f) {s : set β} (hs : is_open s) : s ⊆ closure (f '' (f ⁻¹' s))
by { rw image_preimage_eq_inter_range, exact hf.open_subset_closure_inter hs }
lemma
dense_range.subset_closure_image_preimage_of_is_open
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "closure", "dense_range", "is_open" ]
If `f` has dense range and `s` is an open set in the codomain of `f`, then the image of the preimage of `s` under `f` is dense in `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.dense_of_maps_to {f : α → β} (hf' : dense_range f) (hf : continuous f) {s : set α} (hs : dense s) {t : set β} (ht : maps_to f s t) : dense t
(hf'.dense_image hf hs).mono ht.image_subset
lemma
dense_range.dense_of_maps_to
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "continuous", "dense", "dense_range" ]
If a continuous map with dense range maps a dense set to a subset of `t`, then `t` is a dense set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.comp {g : β → γ} {f : κ → β} (hg : dense_range g) (hf : dense_range f) (cg : continuous g) : dense_range (g ∘ f)
by { rw [dense_range, range_comp], exact hg.dense_image cg hf }
lemma
dense_range.comp
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "continuous", "dense_range" ]
Composition of a continuous map with dense range and a function with dense range has dense range.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.nonempty_iff (hf : dense_range f) : nonempty κ ↔ nonempty β
range_nonempty_iff_nonempty.symm.trans hf.nonempty_iff
lemma
dense_range.nonempty_iff
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "dense_range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.nonempty [h : nonempty β] (hf : dense_range f) : nonempty κ
hf.nonempty_iff.mpr h
lemma
dense_range.nonempty
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "dense_range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.some (hf : dense_range f) (b : β) : κ
classical.choice $ hf.nonempty_iff.mpr ⟨b⟩
def
dense_range.some
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "dense_range" ]
Given a function `f : α → β` with dense range and `b : β`, returns some `a : α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.exists_mem_open (hf : dense_range f) {s : set β} (ho : is_open s) (hs : s.nonempty) : ∃ a, f a ∈ s
exists_range_iff.1 $ hf.exists_mem_open ho hs
lemma
dense_range.exists_mem_open
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "dense_range", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_range.mem_nhds {f : κ → β} (h : dense_range f) {b : β} {U : set β} (U_in : U ∈ 𝓝 b) : ∃ a, f a ∈ U
let ⟨a, ha⟩ := h.exists_mem_open is_open_interior ⟨b, mem_interior_iff_mem_nhds.2 U_in⟩ in ⟨a, interior_subset ha⟩
lemma
dense_range.mem_nhds
topology
src/topology/basic.lean
[ "order.filter.ultrafilter", "algebra.support", "order.filter.lift" ]
[ "dense_range", "interior_subset", "is_open_interior" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_open.gen (s : set α) (u : set β) : set C(α,β)
{f | f '' s ⊆ u}
def
continuous_map.compact_open.gen
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
A generating set for the compact-open topology (when `s` is compact and `u` is open).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gen_empty (u : set β) : compact_open.gen (∅ : set α) u = set.univ
set.ext (λ f, iff_true_intro ((congr_arg (⊆ u) (image_empty f)).mpr u.empty_subset))
lemma
continuous_map.gen_empty
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gen_univ (s : set α) : compact_open.gen s (set.univ : set β) = set.univ
set.ext (λ f, iff_true_intro (f '' s).subset_univ)
lemma
continuous_map.gen_univ
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gen_inter (s : set α) (u v : set β) : compact_open.gen s (u ∩ v) = compact_open.gen s u ∩ compact_open.gen s v
set.ext (λ f, subset_inter_iff)
lemma
continuous_map.gen_inter
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gen_union (s t : set α) (u : set β) : compact_open.gen (s ∪ t) u = compact_open.gen s u ∩ compact_open.gen t u
set.ext (λ f, (iff_of_eq (congr_arg (⊆ u) (image_union f s t))).trans union_subset_iff)
lemma
continuous_map.gen_union
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "iff_of_eq", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gen_empty_right {s : set α} (h : s.nonempty) : compact_open.gen s (∅ : set β) = ∅
eq_empty_of_forall_not_mem $ λ f, (h.image _).not_subset_empty
lemma
continuous_map.gen_empty_right
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_open : topological_space C(α, β)
topological_space.generate_from {m | ∃ (s : set α) (hs : is_compact s) (u : set β) (hu : is_open u), m = compact_open.gen s u}
instance
continuous_map.compact_open
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "is_compact", "is_open", "topological_space", "topological_space.generate_from" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_gen {s : set α} (hs : is_compact s) {u : set β} (hu : is_open u) : is_open (compact_open.gen s u)
topological_space.generate_open.basic _ (by dsimp [mem_set_of_eq]; tauto)
lemma
continuous_map.is_open_gen
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "is_compact", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preimage_gen {s : set α} (hs : is_compact s) {u : set γ} (hu : is_open u) : continuous_map.comp g ⁻¹' (compact_open.gen s u) = compact_open.gen s (g ⁻¹' u)
begin ext ⟨f, _⟩, change g ∘ f '' s ⊆ u ↔ f '' s ⊆ g ⁻¹' u, rw [image_comp, image_subset_iff] end
lemma
continuous_map.preimage_gen
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_map.comp", "is_compact", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_comp : continuous (continuous_map.comp g : C(α, β) → C(α, γ))
continuous_generated_from $ assume m ⟨s, hs, u, hu, hm⟩, by rw [hm, preimage_gen g hs hu]; exact continuous_map.is_open_gen hs (hu.preimage g.2)
lemma
continuous_map.continuous_comp
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_generated_from", "continuous_map.comp", "continuous_map.is_open_gen" ]
C(α, -) is a functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_gen {s : set α} (hs : is_compact s) {u : set γ} (hu : is_open u) : (λ g : C(β, γ), g.comp f) ⁻¹' compact_open.gen s u = compact_open.gen (f '' s) u
begin ext ⟨g, _⟩, change g ∘ f '' s ⊆ u ↔ g '' (f '' s) ⊆ u, rw set.image_comp, end
lemma
continuous_map.image_gen
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "is_compact", "is_open", "set.image_comp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_comp_left : continuous (λ g, g.comp f : C(β, γ) → C(α, γ))
continuous_generated_from $ assume m ⟨s, hs, u, hu, hm⟩, by { rw [hm, image_gen f hs hu], exact continuous_map.is_open_gen (hs.image f.2) hu }
lemma
continuous_map.continuous_comp_left
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_generated_from", "continuous_map.is_open_gen" ]
C(-, γ) is a functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_comp' [locally_compact_space β] : continuous (λ x : C(α, β) × C(β, γ), x.2.comp x.1)
continuous_generated_from begin rintros M ⟨K, hK, U, hU, rfl⟩, conv { congr, rw [compact_open.gen, preimage_set_of_eq], congr, funext, rw [coe_comp, image_comp, image_subset_iff] }, rw is_open_iff_forall_mem_open, rintros ⟨φ₀, ψ₀⟩ H, obtain ⟨L, hL, hKL, hLU⟩ := exists_compact_between (hK.image φ₀.2) (hU.p...
lemma
continuous_map.continuous_comp'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_generated_from", "continuous_map.is_open_gen", "exists_compact_between", "interior", "is_open_iff_forall_mem_open", "is_open_interior", "locally_compact_space", "subset_trans" ]
Composition is a continuous map from `C(α, β) × C(β, γ)` to `C(α, γ)`, provided that `β` is locally compact. This is Prop. 9 of Chap. X, §3, №. 4 of Bourbaki's *Topologie Générale*.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.comp' {X : Type*} [topological_space X] [locally_compact_space β] {f : X → C(α, β)} {g : X → C(β, γ)} (hf : continuous f) (hg : continuous g) : continuous (λ x, (g x).comp (f x))
continuous_comp'.comp (hf.prod_mk hg : continuous $ λ x, (f x, g x))
lemma
continuous_map.continuous.comp'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "locally_compact_space", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_eval' [locally_compact_space α] : continuous (λ p : C(α, β) × α, p.1 p.2)
continuous_iff_continuous_at.mpr $ assume ⟨f, x⟩ n hn, let ⟨v, vn, vo, fxv⟩ := mem_nhds_iff.mp hn in have v ∈ 𝓝 (f x), from is_open.mem_nhds vo fxv, let ⟨s, hs, sv, sc⟩ := locally_compact_space.local_compact_nhds x (f ⁻¹' v) (f.continuous.tendsto x this) in let ⟨u, us, uo, xu⟩ := mem_nhds_iff.mp hs i...
lemma
continuous_map.continuous_eval'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_map.is_open_gen", "is_open", "is_open.mem_nhds", "locally_compact_space" ]
The evaluation map `C(α, β) × α → β` is continuous if `α` is locally compact. See also `continuous_map.continuous_eval`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_eval_const' [locally_compact_space α] (a : α) : continuous (λ f : C(α, β), f a)
continuous_eval'.comp (continuous_id.prod_mk continuous_const)
lemma
continuous_map.continuous_eval_const'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_const", "locally_compact_space" ]
See also `continuous_map.continuous_eval_const`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_coe' [locally_compact_space α] : @continuous (C(α, β)) (α → β) _ _ coe_fn
continuous_pi continuous_eval_const'
lemma
continuous_map.continuous_coe'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_pi", "locally_compact_space" ]
See also `continuous_map.continuous_coe`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_open_le_induced (s : set α) : (continuous_map.compact_open : topological_space C(α, β)) ≤ topological_space.induced (continuous_map.restrict s) continuous_map.compact_open
begin simp only [induced_generate_from_eq, continuous_map.compact_open], apply topological_space.generate_from_anti, rintros b ⟨a, ⟨c, hc, u, hu, rfl⟩, rfl⟩, refine ⟨coe '' c, hc.image continuous_subtype_coe, u, hu, _⟩, ext f, simp only [compact_open.gen, mem_set_of_eq, mem_preimage, continuous_map.coe_rest...
lemma
continuous_map.compact_open_le_induced
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_map.coe_restrict", "continuous_map.compact_open", "continuous_map.restrict", "continuous_subtype_coe", "induced_generate_from_eq", "topological_space", "topological_space.generate_from_anti", "topological_space.induced" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_open_eq_Inf_induced : (continuous_map.compact_open : topological_space C(α, β)) = ⨅ (s : set α) (hs : is_compact s), topological_space.induced (continuous_map.restrict s) continuous_map.compact_open
begin refine le_antisymm _ _, { refine le_infi₂ _, exact λ s hs, compact_open_le_induced s }, simp only [← generate_from_Union, induced_generate_from_eq, continuous_map.compact_open], apply topological_space.generate_from_anti, rintros _ ⟨s, hs, u, hu, rfl⟩, rw mem_Union₂, refine ⟨s, hs, _, ⟨univ, is_...
lemma
continuous_map.compact_open_eq_Inf_induced
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_map.coe_restrict", "continuous_map.compact_open", "continuous_map.restrict", "generate_from_Union", "induced_generate_from_eq", "is_compact", "le_infi₂", "topological_space", "topological_space.generate_from_anti", "topological_space.induced" ]
The compact-open topology on `C(α, β)` is equal to the infimum of the compact-open topologies on `C(s, β)` for `s` a compact subset of `α`. The key point of the proof is that the union of the compact subsets of `α` is equal to the union of compact subsets of the compact subsets of `α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_restrict (s : set α) : continuous (λ F : C(α, β), F.restrict s)
by { rw continuous_iff_le_induced, exact compact_open_le_induced s }
lemma
continuous_map.continuous_restrict
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_iff_le_induced" ]
For any subset `s` of `α`, the restriction of continuous functions to `s` is continuous as a function from `C(α, β)` to `C(s, β)` with their respective compact-open topologies.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_compact_open_eq_Inf_nhds_induced (f : C(α, β)) : 𝓝 f = ⨅ s (hs : is_compact s), (𝓝 (f.restrict s)).comap (continuous_map.restrict s)
by { rw [compact_open_eq_Inf_induced], simp [nhds_infi, nhds_induced] }
lemma
continuous_map.nhds_compact_open_eq_Inf_nhds_induced
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_map.restrict", "is_compact", "nhds_induced", "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_compact_open_restrict {ι : Type*} {l : filter ι} {F : ι → C(α, β)} {f : C(α, β)} (hFf : filter.tendsto F l (𝓝 f)) (s : set α) : filter.tendsto (λ i, (F i).restrict s) l (𝓝 (f.restrict s))
(continuous_restrict s).continuous_at.tendsto.comp hFf
lemma
continuous_map.tendsto_compact_open_restrict
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "filter", "filter.tendsto" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_compact_open_iff_forall {ι : Type*} {l : filter ι} (F : ι → C(α, β)) (f : C(α, β)) : filter.tendsto F l (𝓝 f) ↔ ∀ s (hs : is_compact s), filter.tendsto (λ i, (F i).restrict s) l (𝓝 (f.restrict s))
by { rw [compact_open_eq_Inf_induced], simp [nhds_infi, nhds_induced, filter.tendsto_comap_iff] }
lemma
continuous_map.tendsto_compact_open_iff_forall
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "filter", "filter.tendsto", "filter.tendsto_comap_iff", "is_compact", "nhds_induced", "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_tendsto_compact_open_iff_forall [locally_compact_space α] [t2_space α] [t2_space β] {ι : Type*} {l : filter ι} [filter.ne_bot l] (F : ι → C(α, β)) : (∃ f, filter.tendsto F l (𝓝 f)) ↔ ∀ (s : set α) (hs : is_compact s), ∃ f, filter.tendsto (λ i, (F i).restrict s) l (𝓝 f)
begin split, { rintros ⟨f, hf⟩ s hs, exact ⟨f.restrict s, tendsto_compact_open_restrict hf s⟩ }, { intros h, choose f hf using h, -- By uniqueness of limits in a `t2_space`, since `λ i, F i x` tends to both `f s₁ hs₁ x` and -- `f s₂ hs₂ x`, we have `f s₁ hs₁ x = f s₂ hs₂ x` have h : ∀ s₁ (hs₁ ...
lemma
continuous_map.exists_tendsto_compact_open_iff_forall
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "exists_compact_mem_nhds", "filter", "filter.ne_bot", "filter.tendsto", "is_compact", "locally_compact_space", "t2_space", "tendsto_nhds_unique" ]
A family `F` of functions in `C(α, β)` converges in the compact-open topology, if and only if it converges in the compact-open topology on each compact subset of `α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coev (b : β) : C(α, β × α)
⟨prod.mk b, continuous_const.prod_mk continuous_id⟩
def
continuous_map.coev
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
The coevaluation map `β → C(α, β × α)` sending a point `x : β` to the continuous function on `α` sending `y` to `(x, y)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_coev {y : β} (s : set α) : (coev α β y) '' s = ({y} : set β) ×ˢ s
by tidy
lemma
continuous_map.image_coev
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_coev : continuous (coev α β)
continuous_generated_from $ begin rintros _ ⟨s, sc, u, uo, rfl⟩, rw is_open_iff_forall_mem_open, intros y hy, change (coev α β y) '' s ⊆ u at hy, rw image_coev s at hy, rcases generalized_tube_lemma is_compact_singleton sc uo hy with ⟨v, w, vo, wo, yv, sw, vwu⟩, refine ⟨v, _, vo, singleton_subset_iff....
lemma
continuous_map.continuous_coev
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_generated_from", "generalized_tube_lemma", "is_compact_singleton", "is_open_iff_forall_mem_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry' (f : C(α × β, γ)) (a : α) : C(β, γ)
⟨function.curry f a⟩
def
continuous_map.curry'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
Auxiliary definition, see `continuous_map.curry` and `homeomorph.curry`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_curry' (f : C(α × β, γ)) : continuous (curry' f)
have hf : curry' f = continuous_map.comp f ∘ coev _ _, by { ext, refl }, hf ▸ continuous.comp (continuous_comp f) continuous_coev
lemma
continuous_map.continuous_curry'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous.comp", "continuous_map.comp" ]
If a map `α × β → γ` is continuous, then its curried form `α → C(β, γ)` is continuous.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_of_continuous_uncurry (f : α → C(β, γ)) (h : continuous (function.uncurry (λ x y, f x y))) : continuous f
by { convert continuous_curry' ⟨_, h⟩, ext, refl }
lemma
continuous_map.continuous_of_continuous_uncurry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous" ]
To show continuity of a map `α → C(β, γ)`, it suffices to show that its uncurried form `α × β → γ` is continuous.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry (f : C(α × β, γ)) : C(α, C(β, γ))
⟨_, continuous_curry' f⟩
def
continuous_map.curry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
The curried form of a continuous map `α × β → γ` as a continuous map `α → C(β, γ)`. If `a × β` is locally compact, this is continuous. If `α` and `β` are both locally compact, then this is a homeomorphism, see `homeomorph.curry`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_curry [locally_compact_space (α × β)] : continuous (curry : C(α × β, γ) → C(α, C(β, γ)))
begin apply continuous_of_continuous_uncurry, apply continuous_of_continuous_uncurry, rw ←homeomorph.comp_continuous_iff' (homeomorph.prod_assoc _ _ _).symm, convert continuous_eval'; tidy end
lemma
continuous_map.continuous_curry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_curry", "homeomorph.prod_assoc", "locally_compact_space" ]
The currying process is a continuous map between function spaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry_apply (f : C(α × β, γ)) (a : α) (b : β) : f.curry a b = f (a, b)
rfl
lemma
continuous_map.curry_apply
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "curry_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_uncurry_of_continuous [locally_compact_space β] (f : C(α, C(β, γ))) : continuous (function.uncurry (λ x y, f x y))
continuous_eval'.comp $ f.continuous.prod_map continuous_id
lemma
continuous_map.continuous_uncurry_of_continuous
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_id", "locally_compact_space" ]
The uncurried form of a continuous map `α → C(β, γ)` is a continuous map `α × β → γ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uncurry [locally_compact_space β] (f : C(α, C(β, γ))) : C(α × β, γ)
⟨_, continuous_uncurry_of_continuous f⟩
def
continuous_map.uncurry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "locally_compact_space" ]
The uncurried form of a continuous map `α → C(β, γ)` as a continuous map `α × β → γ` (if `β` is locally compact). If `α` is also locally compact, then this is a homeomorphism between the two function spaces, see `homeomorph.curry`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_uncurry [locally_compact_space α] [locally_compact_space β] : continuous (uncurry : C(α, C(β, γ)) → C(α × β, γ))
begin apply continuous_of_continuous_uncurry, rw ←homeomorph.comp_continuous_iff' (homeomorph.prod_assoc _ _ _), apply continuous.comp continuous_eval' (continuous.prod_map continuous_eval' continuous_id); apply_instance end
lemma
continuous_map.continuous_uncurry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous.comp", "continuous.prod_map", "continuous_id", "homeomorph.prod_assoc", "locally_compact_space" ]
The uncurrying process is a continuous map between function spaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const' : C(β, C(α, β))
curry ⟨prod.fst, continuous_fst⟩
def
continuous_map.const'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
The family of constant maps: `β → C(α, β)` as a continuous map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_const' : (const' : β → C(α, β)) = const α
rfl
lemma
continuous_map.coe_const'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_const' : continuous (const α : β → C(α, β))
const'.continuous
lemma
continuous_map.continuous_const'
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
curry [locally_compact_space α] [locally_compact_space β] : C(α × β, γ) ≃ₜ C(α, C(β, γ))
⟨⟨curry, uncurry, by tidy, by tidy⟩, continuous_curry, continuous_uncurry⟩
def
homeomorph.curry
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_curry", "locally_compact_space" ]
Currying as a homeomorphism between the function spaces `C(α × β, γ)` and `C(α, C(β, γ))`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_map_of_unique [unique α] : β ≃ₜ C(α, β)
{ to_fun := const α, inv_fun := λ f, f default, left_inv := λ a, rfl, right_inv := λ f, by { ext, rw unique.eq_default a, refl }, continuous_to_fun := continuous_const', continuous_inv_fun := continuous_eval'.comp (continuous_id.prod_mk continuous_const) }
def
homeomorph.continuous_map_of_unique
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous_const", "inv_fun", "unique", "unique.eq_default" ]
If `α` has a single element, then `β` is homeomorphic to `C(α, β)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_map_of_unique_apply [unique α] (b : β) (a : α) : continuous_map_of_unique b a = b
rfl
lemma
homeomorph.continuous_map_of_unique_apply
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_map_of_unique_symm_apply [unique α] (f : C(α, β)) : continuous_map_of_unique.symm f = f default
rfl
lemma
homeomorph.continuous_map_of_unique_symm_apply
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "unique" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_map.continuous_lift_prod_left (hf : quotient_map f) {g : X × Y → Z} (hg : continuous (λ p : X₀ × Y, g (f p.1, p.2))) : continuous g
begin let Gf : C(X₀, C(Y, Z)) := continuous_map.curry ⟨_, hg⟩, have h : ∀ x : X, continuous (λ y, g (x, y)), { intros x, obtain ⟨x₀, rfl⟩ := hf.surjective x, exact (Gf x₀).continuous }, let G : X → C(Y, Z) := λ x, ⟨_, h x⟩, have : continuous G, { rw hf.continuous_iff, exact Gf.continuous }, co...
lemma
quotient_map.continuous_lift_prod_left
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_map.continuous_uncurry_of_continuous", "continuous_map.curry", "quotient_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_map.continuous_lift_prod_right (hf : quotient_map f) {g : Y × X → Z} (hg : continuous (λ p : Y × X₀, g (p.1, f p.2))) : continuous g
begin have : continuous (λ p : X₀ × Y, g ((prod.swap p).1, f (prod.swap p).2)), { exact hg.comp continuous_swap }, have : continuous (λ p : X₀ × Y, (g ∘ prod.swap) (f p.1, p.2)) := this, convert (hf.continuous_lift_prod_left this).comp continuous_swap, ext x, simp, end
lemma
quotient_map.continuous_lift_prod_right
topology
src/topology/compact_open.lean
[ "tactic.tidy", "topology.continuous_function.basic", "topology.homeomorph", "topology.subset_properties", "topology.maps" ]
[ "continuous", "continuous_swap", "prod.swap", "quotient_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected (s : set α) : Prop
∀ (u v : set α), is_open u → is_open v → s ⊆ u ∪ v → (s ∩ u).nonempty → (s ∩ v).nonempty → (s ∩ (u ∩ v)).nonempty
def
is_preconnected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_open" ]
A preconnected set is one where there is no non-trivial open partition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected (s : set α) : Prop
s.nonempty ∧ is_preconnected s
def
is_connected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected" ]
A connected set is one that is nonempty and where there is no non-trivial open partition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.nonempty {s : set α} (h : is_connected s) : s.nonempty
h.1
lemma
is_connected.nonempty
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.is_preconnected {s : set α} (h : is_connected s) : is_preconnected s
h.2
lemma
is_connected.is_preconnected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preirreducible.is_preconnected {s : set α} (H : is_preirreducible s) : is_preconnected s
λ _ _ hu hv _, H _ _ hu hv
theorem
is_preirreducible.is_preconnected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preirreducible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_irreducible.is_connected {s : set α} (H : is_irreducible s) : is_connected s
⟨H.nonempty, H.is_preirreducible.is_preconnected⟩
theorem
is_irreducible.is_connected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_irreducible" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_empty : is_preconnected (∅ : set α)
is_preirreducible_empty.is_preconnected
theorem
is_preconnected_empty
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected_singleton {x} : is_connected ({x} : set α)
is_irreducible_singleton.is_connected
theorem
is_connected_singleton
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_singleton {x} : is_preconnected ({x} : set α)
is_connected_singleton.is_preconnected
theorem
is_preconnected_singleton
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set.subsingleton.is_preconnected {s : set α} (hs : s.subsingleton) : is_preconnected s
hs.induction_on is_preconnected_empty (λ x, is_preconnected_singleton)
theorem
set.subsingleton.is_preconnected
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected_empty", "is_preconnected_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_of_forall {s : set α} (x : α) (H : ∀ y ∈ s, ∃ t ⊆ s, x ∈ t ∧ y ∈ t ∧ is_preconnected t) : is_preconnected s
begin rintros u v hu hv hs ⟨z, zs, zu⟩ ⟨y, ys, yv⟩, have xs : x ∈ s, by { rcases H y ys with ⟨t, ts, xt, yt, ht⟩, exact ts xt }, wlog xu : x ∈ u, { rw inter_comm u v, rw union_comm at hs, exact this x H v u hv hu hs y ys yv z zs zu xs ((hs xs).resolve_right xu), }, rcases H y ys with ⟨t, ts, xt, yt, ht⟩, ...
theorem
is_preconnected_of_forall
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected" ]
If any point of a set is joined to a fixed point by a preconnected subset, then the original set is preconnected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_of_forall_pair {s : set α} (H : ∀ x y ∈ s, ∃ t ⊆ s, x ∈ t ∧ y ∈ t ∧ is_preconnected t) : is_preconnected s
begin rcases eq_empty_or_nonempty s with (rfl|⟨x, hx⟩), exacts [is_preconnected_empty, is_preconnected_of_forall x $ λ y, H x hx y], end
theorem
is_preconnected_of_forall_pair
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected_empty", "is_preconnected_of_forall" ]
If any two points of a set are contained in a preconnected subset, then the original set is preconnected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_sUnion (x : α) (c : set (set α)) (H1 : ∀ s ∈ c, x ∈ s) (H2 : ∀ s ∈ c, is_preconnected s) : is_preconnected (⋃₀ c)
begin apply is_preconnected_of_forall x, rintros y ⟨s, sc, ys⟩, exact ⟨s, subset_sUnion_of_mem sc, H1 s sc, ys, H2 s sc⟩ end
theorem
is_preconnected_sUnion
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected_of_forall" ]
A union of a family of preconnected sets with a common point is preconnected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_Union {ι : Sort*} {s : ι → set α} (h₁ : (⋂ i, s i).nonempty) (h₂ : ∀ i, is_preconnected (s i)) : is_preconnected (⋃ i, s i)
exists.elim h₁ $ λ f hf, is_preconnected_sUnion f _ hf (forall_range_iff.2 h₂)
theorem
is_preconnected_Union
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected_sUnion" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.union (x : α) {s t : set α} (H1 : x ∈ s) (H2 : x ∈ t) (H3 : is_preconnected s) (H4 : is_preconnected t) : is_preconnected (s ∪ t)
sUnion_pair s t ▸ is_preconnected_sUnion x {s, t} (by rintro r (rfl | rfl | h); assumption) (by rintro r (rfl | rfl | h); assumption)
theorem
is_preconnected.union
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected_sUnion" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.union' {s t : set α} (H : (s ∩ t).nonempty) (hs : is_preconnected s) (ht : is_preconnected t) : is_preconnected (s ∪ t)
by { rcases H with ⟨x, hxs, hxt⟩, exact hs.union x hxs hxt ht }
theorem
is_preconnected.union'
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.union {s t : set α} (H : (s ∩ t).nonempty) (Hs : is_connected s) (Ht : is_connected t) : is_connected (s ∪ t)
begin rcases H with ⟨x, hx⟩, refine ⟨⟨x, mem_union_left t (mem_of_mem_inter_left hx)⟩, _⟩, exact is_preconnected.union x (mem_of_mem_inter_left hx) (mem_of_mem_inter_right hx) Hs.is_preconnected Ht.is_preconnected end
theorem
is_connected.union
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_preconnected.union" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.sUnion_directed {S : set (set α)} (K : directed_on (⊆) S) (H : ∀ s ∈ S, is_preconnected s) : is_preconnected (⋃₀ S)
begin rintros u v hu hv Huv ⟨a, ⟨s, hsS, has⟩, hau⟩ ⟨b, ⟨t, htS, hbt⟩, hbv⟩, obtain ⟨r, hrS, hsr, htr⟩ : ∃ r ∈ S, s ⊆ r ∧ t ⊆ r := K s hsS t htS, have Hnuv : (r ∩ (u ∩ v)).nonempty, from H _ hrS u v hu hv ((subset_sUnion_of_mem hrS).trans Huv) ⟨a, hsr has, hau⟩ ⟨b, htr hbt, hbv⟩, have Kruv : r ∩ (u ∩ v) ⊆...
theorem
is_preconnected.sUnion_directed
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "directed_on", "is_preconnected" ]
The directed sUnion of a set S of preconnected subsets is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.bUnion_of_refl_trans_gen {ι : Type*} {t : set ι} {s : ι → set α} (H : ∀ i ∈ t, is_preconnected (s i)) (K : ∀ i j ∈ t, refl_trans_gen (λ i j : ι, (s i ∩ s j).nonempty ∧ i ∈ t) i j) : is_preconnected (⋃ n ∈ t, s n)
begin let R := λ i j : ι, (s i ∩ s j).nonempty ∧ i ∈ t, have P : ∀ (i j ∈ t), refl_trans_gen R i j → ∃ (p ⊆ t), i ∈ p ∧ j ∈ p ∧ is_preconnected (⋃ j ∈ p, s j), { intros i hi j hj h, induction h, case refl { refine ⟨{i}, singleton_subset_iff.mpr hi, mem_singleton i, mem_singleton i, _⟩, rw [b...
theorem
is_preconnected.bUnion_of_refl_trans_gen
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "ih", "is_preconnected", "is_preconnected_of_forall_pair" ]
The bUnion of a family of preconnected sets is preconnected if the graph determined by whether two sets intersect is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.bUnion_of_refl_trans_gen {ι : Type*} {t : set ι} {s : ι → set α} (ht : t.nonempty) (H : ∀ i ∈ t, is_connected (s i)) (K : ∀ i j ∈ t, refl_trans_gen (λ i j : ι, (s i ∩ s j).nonempty ∧ i ∈ t) i j) : is_connected (⋃ n ∈ t, s n)
⟨nonempty_bUnion.2 $ ⟨ht.some, ht.some_mem, (H _ ht.some_mem).nonempty⟩, is_preconnected.bUnion_of_refl_trans_gen (λ i hi, (H i hi).is_preconnected) K⟩
theorem
is_connected.bUnion_of_refl_trans_gen
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_preconnected", "is_preconnected.bUnion_of_refl_trans_gen" ]
The bUnion of a family of preconnected sets is preconnected if the graph determined by whether two sets intersect is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.Union_of_refl_trans_gen {ι : Type*} {s : ι → set α} (H : ∀ i, is_preconnected (s i)) (K : ∀ i j, refl_trans_gen (λ i j : ι, (s i ∩ s j).nonempty) i j) : is_preconnected (⋃ n, s n)
by { rw [← bUnion_univ], exact is_preconnected.bUnion_of_refl_trans_gen (λ i _, H i) (λ i _ j _, by simpa [mem_univ] using K i j) }
theorem
is_preconnected.Union_of_refl_trans_gen
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected.bUnion_of_refl_trans_gen" ]
Preconnectedness of the Union of a family of preconnected sets indexed by the vertices of a preconnected graph, where two vertices are joined when the corresponding sets intersect.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.Union_of_refl_trans_gen {ι : Type*} [nonempty ι] {s : ι → set α} (H : ∀ i, is_connected (s i)) (K : ∀ i j, refl_trans_gen (λ i j : ι, (s i ∩ s j).nonempty) i j) : is_connected (⋃ n, s n)
⟨nonempty_Union.2 $ nonempty.elim ‹_› $ λ i : ι, ⟨i, (H _).nonempty⟩, is_preconnected.Union_of_refl_trans_gen (λ i, (H i).is_preconnected) K⟩
theorem
is_connected.Union_of_refl_trans_gen
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_preconnected", "is_preconnected.Union_of_refl_trans_gen" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.Union_of_chain {s : β → set α} (H : ∀ n, is_preconnected (s n)) (K : ∀ n, (s n ∩ s (succ n)).nonempty) : is_preconnected (⋃ n, s n)
is_preconnected.Union_of_refl_trans_gen H $ λ i j, refl_trans_gen_of_succ _ (λ i _, K i) $ λ i _, by { rw inter_comm, exact K i }
theorem
is_preconnected.Union_of_chain
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected.Union_of_refl_trans_gen", "refl_trans_gen_of_succ" ]
The Union of connected sets indexed by a type with an archimedean successor (like `ℕ` or `ℤ`) such that any two neighboring sets meet is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.Union_of_chain [nonempty β] {s : β → set α} (H : ∀ n, is_connected (s n)) (K : ∀ n, (s n ∩ s (succ n)).nonempty) : is_connected (⋃ n, s n)
is_connected.Union_of_refl_trans_gen H $ λ i j, refl_trans_gen_of_succ _ (λ i _, K i) $ λ i _, by { rw inter_comm, exact K i }
theorem
is_connected.Union_of_chain
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_connected.Union_of_refl_trans_gen", "refl_trans_gen_of_succ" ]
The Union of connected sets indexed by a type with an archimedean successor (like `ℕ` or `ℤ`) such that any two neighboring sets meet is connected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.bUnion_of_chain {s : β → set α} {t : set β} (ht : ord_connected t) (H : ∀ n ∈ t, is_preconnected (s n)) (K : ∀ n : β, n ∈ t → succ n ∈ t → (s n ∩ s (succ n)).nonempty) : is_preconnected (⋃ n ∈ t, s n)
begin have h1 : ∀ {i j k : β}, i ∈ t → j ∈ t → k ∈ Ico i j → k ∈ t := λ i j k hi hj hk, ht.out hi hj (Ico_subset_Icc_self hk), have h2 : ∀ {i j k : β}, i ∈ t → j ∈ t → k ∈ Ico i j → succ k ∈ t := λ i j k hi hj hk, ht.out hi hj ⟨hk.1.trans $ le_succ k, succ_le_of_lt hk.2⟩, have h3 : ∀ {i j k : β}, i ∈ t → ...
theorem
is_preconnected.bUnion_of_chain
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_preconnected", "is_preconnected.bUnion_of_refl_trans_gen", "refl_trans_gen_of_succ" ]
The Union of preconnected sets indexed by a subset of a type with an archimedean successor (like `ℕ` or `ℤ`) such that any two neighboring sets meet is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.bUnion_of_chain {s : β → set α} {t : set β} (hnt : t.nonempty) (ht : ord_connected t) (H : ∀ n ∈ t, is_connected (s n)) (K : ∀ n : β, n ∈ t → succ n ∈ t → (s n ∩ s (succ n)).nonempty) : is_connected (⋃ n ∈ t, s n)
⟨nonempty_bUnion.2 $ ⟨hnt.some, hnt.some_mem, (H _ hnt.some_mem).nonempty⟩, is_preconnected.bUnion_of_chain ht (λ i hi, (H i hi).is_preconnected) K⟩
theorem
is_connected.bUnion_of_chain
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_preconnected", "is_preconnected.bUnion_of_chain" ]
The Union of connected sets indexed by a subset of a type with an archimedean successor (like `ℕ` or `ℤ`) such that any two neighboring sets meet is preconnected.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.subset_closure {s : set α} {t : set α} (H : is_preconnected s) (Kst : s ⊆ t) (Ktcs : t ⊆ closure s) : is_preconnected t
λ u v hu hv htuv ⟨y, hyt, hyu⟩ ⟨z, hzt, hzv⟩, let ⟨p, hpu, hps⟩ := mem_closure_iff.1 (Ktcs hyt) u hu hyu, ⟨q, hqv, hqs⟩ := mem_closure_iff.1 (Ktcs hzt) v hv hzv, ⟨r, hrs, hruv⟩ := H u v hu hv (subset.trans Kst htuv) ⟨p, hps, hpu⟩ ⟨q, hqs, hqv⟩ in ⟨r, Kst hrs, hruv⟩
theorem
is_preconnected.subset_closure
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "closure", "is_preconnected" ]
Theorem of bark and tree : if a set is within a (pre)connected set and its closure, then it is (pre)connected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.subset_closure {s : set α} {t : set α} (H : is_connected s) (Kst : s ⊆ t) (Ktcs : t ⊆ closure s): is_connected t
let hsne := H.left, ht := Kst, htne := nonempty.mono ht hsne in ⟨nonempty.mono Kst H.left, is_preconnected.subset_closure H.right Kst Ktcs ⟩
theorem
is_connected.subset_closure
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "closure", "is_connected", "is_preconnected.subset_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.closure {s : set α} (H : is_preconnected s) : is_preconnected (closure s)
is_preconnected.subset_closure H subset_closure $ subset.refl $ closure s
theorem
is_preconnected.closure
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "closure", "is_preconnected", "is_preconnected.subset_closure", "subset_closure" ]
The closure of a (pre)connected set is (pre)connected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.closure {s : set α} (H : is_connected s) : is_connected (closure s)
is_connected.subset_closure H subset_closure $ subset.refl $ closure s
theorem
is_connected.closure
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "closure", "is_connected", "is_connected.subset_closure", "subset_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.image [topological_space β] {s : set α} (H : is_preconnected s) (f : α → β) (hf : continuous_on f s) : is_preconnected (f '' s)
begin -- Unfold/destruct definitions in hypotheses rintros u v hu hv huv ⟨_, ⟨x, xs, rfl⟩, xu⟩ ⟨_, ⟨y, ys, rfl⟩, yv⟩, rcases continuous_on_iff'.1 hf u hu with ⟨u', hu', u'_eq⟩, rcases continuous_on_iff'.1 hf v hv with ⟨v', hv', v'_eq⟩, -- Reformulate `huv : f '' s ⊆ u ∪ v` in terms of `u'` and `v'` replace ...
theorem
is_preconnected.image
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "continuous_on", "is_preconnected", "topological_space" ]
The image of a (pre)connected set is (pre)connected as well.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.image [topological_space β] {s : set α} (H : is_connected s) (f : α → β) (hf : continuous_on f s) : is_connected (f '' s)
⟨nonempty_image_iff.mpr H.nonempty, H.is_preconnected.image f hf⟩
theorem
is_connected.image
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "continuous_on", "is_connected", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_closed_iff {s : set α} : is_preconnected s ↔ ∀ t t', is_closed t → is_closed t' → s ⊆ t ∪ t' → (s ∩ t).nonempty → (s ∩ t').nonempty → (s ∩ (t ∩ t')).nonempty
⟨begin rintros h t t' ht ht' htt' ⟨x, xs, xt⟩ ⟨y, ys, yt'⟩, rw [←not_disjoint_iff_nonempty_inter, ←subset_compl_iff_disjoint_right, compl_inter], intros h', have xt' : x ∉ t', from (h' xs).resolve_left (absurd xt), have yt : y ∉ t, from (h' ys).resolve_right (absurd yt'), have := h _ _ ht.is_open_compl ht'....
theorem
is_preconnected_closed_iff
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_closed", "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inducing.is_preconnected_image [topological_space β] {s : set α} {f : α → β} (hf : inducing f) : is_preconnected (f '' s) ↔ is_preconnected s
begin refine ⟨λ h, _, λ h, h.image _ hf.continuous.continuous_on⟩, rintro u v hu' hv' huv ⟨x, hxs, hxu⟩ ⟨y, hys, hyv⟩, rcases hf.is_open_iff.1 hu' with ⟨u, hu, rfl⟩, rcases hf.is_open_iff.1 hv' with ⟨v, hv, rfl⟩, replace huv : f '' s ⊆ u ∪ v, by rwa image_subset_iff, rcases h u v hu hv huv ⟨f x, mem_image_o...
lemma
inducing.is_preconnected_image
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "inducing", "is_preconnected", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.preimage_of_open_map [topological_space β] {s : set β} (hs : is_preconnected s) {f : α → β} (hinj : function.injective f) (hf : is_open_map f) (hsf : s ⊆ range f) : is_preconnected (f ⁻¹' s)
λ u v hu hv hsuv hsu hsv, begin obtain ⟨b, hbs, hbu, hbv⟩ := hs (f '' u) (f '' v) (hf u hu) (hf v hv) _ _ _, obtain ⟨a, rfl⟩ := hsf hbs, rw hinj.mem_set_image at hbu hbv, exact ⟨a, hbs, hbu, hbv⟩, { have := image_subset f hsuv, rwa [set.image_preimage_eq_of_subset hsf, image_union] at this }, { obtain ⟨...
lemma
is_preconnected.preimage_of_open_map
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_open_map", "is_preconnected", "set.image_preimage_eq_of_subset", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.preimage_of_closed_map [topological_space β] {s : set β} (hs : is_preconnected s) {f : α → β} (hinj : function.injective f) (hf : is_closed_map f) (hsf : s ⊆ range f) : is_preconnected (f ⁻¹' s)
is_preconnected_closed_iff.2 $ λ u v hu hv hsuv hsu hsv, begin obtain ⟨b, hbs, hbu, hbv⟩ := is_preconnected_closed_iff.1 hs (f '' u) (f '' v) (hf u hu) (hf v hv) _ _ _, obtain ⟨a, rfl⟩ := hsf hbs, rw hinj.mem_set_image at hbu hbv, exact ⟨a, hbs, hbu, hbv⟩, { have := image_subset f hsuv, rwa [set.image...
lemma
is_preconnected.preimage_of_closed_map
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_closed_map", "is_preconnected", "set.image_preimage_eq_of_subset", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.preimage_of_open_map [topological_space β] {s : set β} (hs : is_connected s) {f : α → β} (hinj : function.injective f) (hf : is_open_map f) (hsf : s ⊆ range f) : is_connected (f ⁻¹' s)
⟨hs.nonempty.preimage' hsf, hs.is_preconnected.preimage_of_open_map hinj hf hsf⟩
lemma
is_connected.preimage_of_open_map
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_open_map", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.preimage_of_closed_map [topological_space β] {s : set β} (hs : is_connected s) {f : α → β} (hinj : function.injective f) (hf : is_closed_map f) (hsf : s ⊆ range f) : is_connected (f ⁻¹' s)
⟨hs.nonempty.preimage' hsf, hs.is_preconnected.preimage_of_closed_map hinj hf hsf⟩
lemma
is_connected.preimage_of_closed_map
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_closed_map", "is_connected", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.subset_or_subset (hu : is_open u) (hv : is_open v) (huv : disjoint u v) (hsuv : s ⊆ u ∪ v) (hs : is_preconnected s) : s ⊆ u ∨ s ⊆ v
begin specialize hs u v hu hv hsuv, obtain hsu | hsu := (s ∩ u).eq_empty_or_nonempty, { exact or.inr ((set.disjoint_iff_inter_eq_empty.2 hsu).subset_right_of_subset_union hsuv) }, { replace hs := mt (hs hsu), simp_rw [set.not_nonempty_iff_eq_empty, ←set.disjoint_iff_inter_eq_empty, disjoint_iff_inter_...
lemma
is_preconnected.subset_or_subset
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "disjoint", "is_open", "is_preconnected", "set.not_nonempty_iff_eq_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.subset_left_of_subset_union (hu : is_open u) (hv : is_open v) (huv : disjoint u v) (hsuv : s ⊆ u ∪ v) (hsu : (s ∩ u).nonempty) (hs : is_preconnected s) : s ⊆ u
disjoint.subset_left_of_subset_union hsuv begin by_contra hsv, rw not_disjoint_iff_nonempty_inter at hsv, obtain ⟨x, _, hx⟩ := hs u v hu hv hsuv hsu hsv, exact set.disjoint_iff.1 huv hx, end
lemma
is_preconnected.subset_left_of_subset_union
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "by_contra", "disjoint", "disjoint.subset_left_of_subset_union", "is_open", "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.subset_right_of_subset_union (hu : is_open u) (hv : is_open v) (huv : disjoint u v) (hsuv : s ⊆ u ∪ v) (hsv : (s ∩ v).nonempty) (hs : is_preconnected s) : s ⊆ v
hs.subset_left_of_subset_union hv hu huv.symm (union_comm u v ▸ hsuv) hsv
lemma
is_preconnected.subset_right_of_subset_union
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "disjoint", "is_open", "is_preconnected" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.subset_of_closure_inter_subset (hs : is_preconnected s) (hu : is_open u) (h'u : (s ∩ u).nonempty) (h : closure u ∩ s ⊆ u) : s ⊆ u
begin have A : s ⊆ u ∪ (closure u)ᶜ, { assume x hx, by_cases xu : x ∈ u, { exact or.inl xu }, { right, assume h'x, exact xu (h (mem_inter h'x hx)) } }, apply hs.subset_left_of_subset_union hu is_closed_closure.is_open_compl _ A h'u, exact disjoint_compl_right.mono_right (compl_subset_com...
lemma
is_preconnected.subset_of_closure_inter_subset
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "closure", "is_open", "is_preconnected", "subset_closure" ]
If a preconnected set `s` intersects an open set `u`, and limit points of `u` inside `s` are contained in `u`, then the whole set `s` is contained in `u`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.prod [topological_space β] {s : set α} {t : set β} (hs : is_preconnected s) (ht : is_preconnected t) : is_preconnected (s ×ˢ t)
begin apply is_preconnected_of_forall_pair, rintro ⟨a₁, b₁⟩ ⟨ha₁, hb₁⟩ ⟨a₂, b₂⟩ ⟨ha₂, hb₂⟩, refine ⟨prod.mk a₁ '' t ∪ flip prod.mk b₂ '' s, _, or.inl ⟨b₁, hb₁, rfl⟩, or.inr ⟨a₂, ha₂, rfl⟩, _⟩, { rintro _ (⟨y, hy, rfl⟩|⟨x, hx, rfl⟩), exacts [⟨ha₁, hy⟩, ⟨hx, hb₂⟩] }, { exact (ht.image _ (continuous.prod...
theorem
is_preconnected.prod
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "continuous.prod.mk", "continuous_const", "continuous_on", "is_preconnected", "is_preconnected_of_forall_pair", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected.prod [topological_space β] {s : set α} {t : set β} (hs : is_connected s) (ht : is_connected t) : is_connected (s ×ˢ t)
⟨hs.1.prod ht.1, hs.2.prod ht.2⟩
theorem
is_connected.prod
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected_univ_pi [Π i, topological_space (π i)] {s : Π i, set (π i)} (hs : ∀ i, is_preconnected (s i)) : is_preconnected (pi univ s)
begin rintros u v uo vo hsuv ⟨f, hfs, hfu⟩ ⟨g, hgs, hgv⟩, rcases exists_finset_piecewise_mem_of_mem_nhds (uo.mem_nhds hfu) g with ⟨I, hI⟩, induction I using finset.induction_on with i I hi ihI, { refine ⟨g, hgs, ⟨_, hgv⟩⟩, simpa using hI }, { rw [finset.piecewise_insert] at hI, have := I.piecewise_mem_set...
theorem
is_preconnected_univ_pi
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "continuous_id", "continuous_on", "exists_finset_piecewise_mem_of_mem_nhds", "finset.induction_on", "finset.piecewise_insert", "is_preconnected", "topological_space", "update", "update_eq_self" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_connected_univ_pi [Π i, topological_space (π i)] {s : Π i, set (π i)} : is_connected (pi univ s) ↔ ∀ i, is_connected (s i)
begin simp only [is_connected, ← univ_pi_nonempty_iff, forall_and_distrib, and.congr_right_iff], refine λ hne, ⟨λ hc i, _, is_preconnected_univ_pi⟩, rw [← eval_image_univ_pi hne], exact hc.image _ (continuous_apply _).continuous_on end
theorem
is_connected_univ_pi
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "and.congr_right_iff", "continuous_apply", "continuous_on", "forall_and_distrib", "is_connected", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sigma.is_connected_iff [Π i, topological_space (π i)] {s : set (Σ i, π i)} : is_connected s ↔ ∃ i t, is_connected t ∧ s = sigma.mk i '' t
begin refine ⟨λ hs, _, _⟩, { obtain ⟨⟨i, x⟩, hx⟩ := hs.nonempty, have : s ⊆ range (sigma.mk i), { have h : range (sigma.mk i) = sigma.fst ⁻¹' {i}, by { ext, simp }, rw h, exact is_preconnected.subset_left_of_subset_union (is_open_sigma_fst_preimage _) (is_open_sigma_fst_preimage {x | x ≠...
lemma
sigma.is_connected_iff
topology
src/topology/connected.lean
[ "data.set.bool_indicator", "order.succ_pred.relation", "topology.subset_properties", "tactic.congrm" ]
[ "is_connected", "is_open_map_sigma_mk", "is_open_sigma_fst_preimage", "is_preconnected.subset_left_of_subset_union", "set.image_preimage_eq_of_subset", "sigma_mk_injective", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83