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continuous_quot_mk : continuous (@quot.mk α r)
continuous_coinduced_rng
lemma
continuous_quot_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_coinduced_rng" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_quot_lift {f : α → β} (hr : ∀ a b, r a b → f a = f b) (h : continuous f) : continuous (quot.lift f hr : quot r → β)
continuous_coinduced_dom.2 h
lemma
continuous_quot_lift
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
quotient_map_quotient_mk : quotient_map (@quotient.mk α s)
quotient_map_quot_mk
lemma
quotient_map_quotient_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "quotient_map", "quotient_map_quot_mk" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_quotient_mk : continuous (@quotient.mk α s)
continuous_coinduced_rng
lemma
continuous_quotient_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_coinduced_rng" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.quotient_lift {f : α → β} (h : continuous f) (hs : ∀ a b, a ≈ b → f a = f b) : continuous (quotient.lift f hs : quotient s → β)
continuous_coinduced_dom.2 h
lemma
continuous.quotient_lift
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.quotient_lift_on' {f : α → β} (h : continuous f) (hs : ∀ a b, @setoid.r _ s a b → f a = f b) : continuous (λ x, quotient.lift_on' x f hs : quotient s → β)
h.quotient_lift hs
lemma
continuous.quotient_lift_on'
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "quotient.lift_on'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.quotient_map' {t : setoid β} {f : α → β} (hf : continuous f) (H : (s.r ⇒ t.r) f f) : continuous (quotient.map' f H)
(continuous_quotient_mk.comp hf).quotient_lift _
lemma
continuous.quotient_map'
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "quotient.map'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_pi_iff : continuous f ↔ ∀ i, continuous (λ a, f a i)
by simp only [continuous_infi_rng, continuous_induced_rng]
lemma
continuous_pi_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_induced_rng", "continuous_infi_rng" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_pi (h : ∀ i, continuous (λ a, f a i)) : continuous f
continuous_pi_iff.2 h
lemma
continuous_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_apply (i : ι) : continuous (λp:Πi, π i, p i)
continuous_infi_dom continuous_induced_dom
lemma
continuous_apply
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_induced_dom", "continuous_infi_dom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_apply_apply {ρ : κ → ι → Type*} [∀ j i, topological_space (ρ j i)] (j : κ) (i : ι) : continuous (λ p : (Π j, Π i, ρ j i), p j i)
(continuous_apply i).comp (continuous_apply j)
lemma
continuous_apply_apply
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_apply", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_apply (i : ι) (x : Π i, π i) : continuous_at (λ p : Π i, π i, p i) x
(continuous_apply i).continuous_at
lemma
continuous_at_apply
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_apply", "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.apply {l : filter β} {f : β → Π i, π i} {x : Π i, π i} (h : tendsto f l (𝓝 x)) (i : ι) : tendsto (λ a, f a i) l (𝓝 $ x i)
(continuous_at_apply i _).tendsto.comp h
lemma
filter.tendsto.apply
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_at_apply", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_pi {a : Πi, π i} : 𝓝 a = pi (λ i, 𝓝 (a i))
by simp only [nhds_infi, nhds_induced, filter.pi]
lemma
nhds_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "filter.pi", "nhds_induced", "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_pi_nhds {f : β → Πi, π i} {g : Πi, π i} {u : filter β} : tendsto f u (𝓝 g) ↔ ∀ x, tendsto (λ i, f i x) u (𝓝 (g x))
by rw [nhds_pi, filter.tendsto_pi]
lemma
tendsto_pi_nhds
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "filter", "filter.tendsto_pi", "nhds_pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_pi {f : α → Π i, π i} {x : α} : continuous_at f x ↔ ∀ i, continuous_at (λ y, f y i) x
tendsto_pi_nhds
lemma
continuous_at_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_at", "tendsto_pi_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.update [decidable_eq ι] {l : filter β} {f : β → Π i, π i} {x : Π i, π i} (hf : tendsto f l (𝓝 x)) (i : ι) {g : β → π i} {xi : π i} (hg : tendsto g l (𝓝 xi)) : tendsto (λ a, update (f a) i (g a)) l (𝓝 $ update x i xi)
tendsto_pi_nhds.2 $ λ j, by { rcases em (j = i) with rfl|hj; simp [*, hf.apply] }
lemma
filter.tendsto.update
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "em", "filter", "update" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.update [decidable_eq ι] {a : α} (hf : continuous_at f a) (i : ι) {g : α → π i} (hg : continuous_at g a) : continuous_at (λ a, update (f a) i (g a)) a
hf.update i hg
lemma
continuous_at.update
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_at", "update" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.update [decidable_eq ι] (hf : continuous f) (i : ι) {g : α → π i} (hg : continuous g) : continuous (λ a, update (f a) i (g a))
continuous_iff_continuous_at.2 $ λ x, hf.continuous_at.update i hg.continuous_at
lemma
continuous.update
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "update" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_update [decidable_eq ι] (i : ι) : continuous (λ f : (Π j, π j) × π i, update f.1 i f.2)
continuous_fst.update i continuous_snd
lemma
continuous_update
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_snd", "update" ]
`function.update f i x` is continuous in `(f, x)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_mul_single [Π i, has_one (π i)] [decidable_eq ι] (i : ι) : continuous (λ x, (pi.mul_single i x : Π i, π i))
continuous_const.update _ continuous_id
lemma
continuous_mul_single
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_id", "pi.mul_single" ]
`pi.mul_single i x` is continuous in `x`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.fin_insert_nth {n} {π : fin (n + 1) → Type*} [Π i, topological_space (π i)] (i : fin (n + 1)) {f : β → π i} {l : filter β} {x : π i} (hf : tendsto f l (𝓝 x)) {g : β → Π j : fin n, π (i.succ_above j)} {y : Π j, π (i.succ_above j)} (hg : tendsto g l (𝓝 y)) : tendsto (λ a, i.insert_nth (f a) (g a)) ...
tendsto_pi_nhds.2 (λ j, fin.succ_above_cases i (by simpa) (by simpa using tendsto_pi_nhds.1 hg) j)
lemma
filter.tendsto.fin_insert_nth
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "filter", "fin.succ_above_cases", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.fin_insert_nth {n} {π : fin (n + 1) → Type*} [Π i, topological_space (π i)] (i : fin (n + 1)) {f : α → π i} {a : α} (hf : continuous_at f a) {g : α → Π j : fin n, π (i.succ_above j)} (hg : continuous_at g a) : continuous_at (λ a, i.insert_nth (f a) (g a)) a
hf.fin_insert_nth i hg
lemma
continuous_at.fin_insert_nth
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_at", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.fin_insert_nth {n} {π : fin (n + 1) → Type*} [Π i, topological_space (π i)] (i : fin (n + 1)) {f : α → π i} (hf : continuous f) {g : α → Π j : fin n, π (i.succ_above j)} (hg : continuous g) : continuous (λ a, i.insert_nth (f a) (g a))
continuous_iff_continuous_at.2 $ λ a, hf.continuous_at.fin_insert_nth i hg.continuous_at
lemma
continuous.fin_insert_nth
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_set_pi {i : set ι} {s : Πa, set (π a)} (hi : i.finite) (hs : ∀a∈i, is_open (s a)) : is_open (pi i s)
by rw [pi_def]; exact (is_open_bInter hi $ assume a ha, (hs _ ha).preimage (continuous_apply _))
lemma
is_open_set_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_apply", "is_open", "is_open_bInter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_pi_iff {s : set (Π a, π a)} : is_open s ↔ (∀ f, f ∈ s → ∃ (I : finset ι) (u : Π a, set (π a)), (∀ a, a ∈ I → is_open (u a) ∧ f a ∈ u a) ∧ (I : set ι).pi u ⊆ s)
begin rw is_open_iff_nhds, simp_rw [le_principal_iff, nhds_pi, filter.mem_pi', mem_nhds_iff, exists_prop], refine ball_congr (λ a h, ⟨_, _⟩), { rintros ⟨I, t, ⟨h1, h2⟩⟩, refine ⟨I, λ a, eval a '' ((I : set ι).pi (λ a, (h1 a).some)), (λ i hi, _), _⟩, { simp_rw set.eval_image_pi (finset.mem_coe.mpr hi) ...
lemma
is_open_pi_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "ball_congr", "exists_prop", "filter.mem_pi'", "finset", "finset.mem_coe", "is_open", "is_open_iff_nhds", "is_open_univ", "ite_and", "mem_nhds_iff", "nhds_pi", "set.eval_image_pi", "set.eval_image_pi_subset", "set.pi_mono", "set.univ_pi_ite" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_pi_iff' [finite ι] {s : set (Π a, π a)} : is_open s ↔ (∀ f, f ∈ s → ∃ (u : Π a, set (π a)), (∀ a, is_open (u a) ∧ f a ∈ u a) ∧ set.univ.pi u ⊆ s)
begin casesI nonempty_fintype ι, rw is_open_iff_nhds, simp_rw [le_principal_iff, nhds_pi, filter.mem_pi', mem_nhds_iff, exists_prop], refine ball_congr (λ a h, ⟨_, _⟩), { rintros ⟨I, t, ⟨h1, h2⟩⟩, refine ⟨λ i, (h1 i).some, ⟨λ i, (h1 i).some_spec.2, (set.pi_mono (λ i _, (h1 i).some_spec.1)).trans (...
lemma
is_open_pi_iff'
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "ball_congr", "exists_prop", "filter.mem_pi'", "finite", "is_open", "is_open_iff_nhds", "mem_nhds_iff", "nhds_pi", "nonempty_fintype", "set.pi_inter_compl", "set.pi_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_closed_set_pi {i : set ι} {s : Πa, set (π a)} (hs : ∀a∈i, is_closed (s a)) : is_closed (pi i s)
by rw [pi_def]; exact (is_closed_Inter $ λ a, is_closed_Inter $ λ ha, (hs _ ha).preimage (continuous_apply _))
lemma
is_closed_set_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_apply", "is_closed", "is_closed_Inter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_of_pi_mem_nhds {I : set ι} {s : Π i, set (π i)} (a : Π i, π i) (hs : I.pi s ∈ 𝓝 a) {i : ι} (hi : i ∈ I) : s i ∈ 𝓝 (a i)
by { rw nhds_pi at hs, exact mem_of_pi_mem_pi hs hi }
lemma
mem_nhds_of_pi_mem_nhds
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "nhds_pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_pi_mem_nhds {i : set ι} {s : Π a, set (π a)} {x : Π a, π a} (hi : i.finite) (hs : ∀ a ∈ i, s a ∈ 𝓝 (x a)) : pi i s ∈ 𝓝 x
by { rw [pi_def, bInter_mem hi], exact λ a ha, (continuous_apply a).continuous_at (hs a ha) }
lemma
set_pi_mem_nhds
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_apply", "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set_pi_mem_nhds_iff {I : set ι} (hI : I.finite) {s : Π i, set (π i)} (a : Π i, π i) : I.pi s ∈ 𝓝 a ↔ ∀ (i : ι), i ∈ I → s i ∈ 𝓝 (a i)
by { rw [nhds_pi, pi_mem_pi_iff hI], apply_instance }
lemma
set_pi_mem_nhds_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "nhds_pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
interior_pi_set {I : set ι} (hI : I.finite) {s : Π i, set (π i)} : interior (pi I s) = I.pi (λ i, interior (s i))
by { ext a, simp only [set.mem_pi, mem_interior_iff_mem_nhds, set_pi_mem_nhds_iff hI] }
lemma
interior_pi_set
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "interior", "mem_interior_iff_mem_nhds", "set.mem_pi", "set_pi_mem_nhds_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_finset_piecewise_mem_of_mem_nhds [decidable_eq ι] {s : set (Π a, π a)} {x : Π a, π a} (hs : s ∈ 𝓝 x) (y : Π a, π a) : ∃ I : finset ι, I.piecewise x y ∈ s
begin simp only [nhds_pi, filter.mem_pi'] at hs, rcases hs with ⟨I, t, htx, hts⟩, refine ⟨I, hts $ λ i hi, _⟩, simpa [finset.mem_coe.1 hi] using mem_of_mem_nhds (htx i) end
lemma
exists_finset_piecewise_mem_of_mem_nhds
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "filter.mem_pi'", "finset", "mem_of_mem_nhds", "nhds_pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_eq_generate_from : Pi.topological_space = generate_from {g | ∃(s:Πa, set (π a)) (i : finset ι), (∀a∈i, is_open (s a)) ∧ g = pi ↑i s}
le_antisymm (le_generate_from $ assume g ⟨s, i, hi, eq⟩, eq.symm ▸ is_open_set_pi (finset.finite_to_set _) hi) (le_infi $ assume a s ⟨t, ht, s_eq⟩, generate_open.basic _ $ ⟨update (λa, univ) a t, {a}, by simpa using ht, s_eq ▸ by ext f; simp [set.pi]⟩)
lemma
pi_eq_generate_from
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "Pi.topological_space", "finset", "finset.finite_to_set", "is_open", "is_open_set_pi", "le_generate_from", "le_infi", "set.pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_generate_from_eq {π : ι → Type*} {g : Πa, set (set (π a))} : @Pi.topological_space ι π (λa, generate_from (g a)) = generate_from {t | ∃(s:Πa, set (π a)) (i : finset ι), (∀a∈i, s a ∈ g a) ∧ t = pi ↑i s}
let G := {t | ∃(s:Πa, set (π a)) (i : finset ι), (∀a∈i, s a ∈ g a) ∧ t = pi ↑i s} in begin rw [pi_eq_generate_from], refine le_antisymm (generate_from_anti _) (le_generate_from _), exact assume s ⟨t, i, ht, eq⟩, ⟨t, i, assume a ha, generate_open.basic _ (ht a ha), eq⟩, { rintros s ⟨t, i, hi, rfl⟩, rw [pi_de...
lemma
pi_generate_from_eq
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "Pi.topological_space", "finset", "finset.finite_to_set", "is_open", "is_open_bInter", "le_generate_from", "pi_eq_generate_from" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_generate_from_eq_finite {π : ι → Type*} {g : Πa, set (set (π a))} [finite ι] (hg : ∀a, ⋃₀ g a = univ) : @Pi.topological_space ι π (λa, generate_from (g a)) = generate_from {t | ∃(s:Πa, set (π a)), (∀a, s a ∈ g a) ∧ t = pi univ s}
begin casesI nonempty_fintype ι, rw [pi_generate_from_eq], refine le_antisymm (generate_from_anti _) (le_generate_from _), { rintro s ⟨t, ht, rfl⟩, exact ⟨t, finset.univ, by simp [ht]⟩ }, { rintros s ⟨t, i, ht, rfl⟩, apply is_open_iff_forall_mem_open.2 _, assume f hf, choose c hc using show ∀a, ∃s...
lemma
pi_generate_from_eq_finite
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "Pi.topological_space", "finite", "finset.univ", "le_generate_from", "nonempty_fintype", "pi_generate_from_eq", "set.pi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inducing_infi_to_pi {X : Type*} (f : Π i, X → π i) : @inducing X (Π i, π i) (⨅ i, induced (f i) infer_instance) _ (λ x i, f i x)
begin constructor, erw induced_infi, congr' 1, funext, erw induced_compose, end
lemma
inducing_infi_to_pi
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "induced_compose", "induced_infi", "inducing" ]
Suppose `π i` is a family of topological spaces indexed by `i : ι`, and `X` is a type endowed with a family of maps `f i : X → π i` for every `i : ι`, hence inducing a map `g : X → Π i, π i`. This lemma shows that infimum of the topologies on `X` induced by the `f i` as `i : ι` varies is simply the topology on `X` indu...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Pi.discrete_topology : discrete_topology (Π i, π i)
singletons_open_iff_discrete.mp (λ x, begin rw show {x} = ⋂ i, {y : Π i, π i | y i = x i}, { ext, simp only [funext_iff, set.mem_singleton_iff, set.mem_Inter, set.mem_set_of_eq] }, exact is_open_Inter (λ i, (continuous_apply i).is_open_preimage {x i} (is_open_discrete {x i})) end)
instance
Pi.discrete_topology
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_apply", "discrete_topology", "is_open_Inter", "is_open_discrete", "set.mem_Inter", "set.mem_singleton_iff" ]
A finite product of discrete spaces is discrete.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_sigma_mk {i : ι} : continuous (@sigma.mk ι σ i)
continuous_supr_rng continuous_coinduced_rng
lemma
continuous_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_coinduced_rng", "continuous_supr_rng" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_sigma_iff {s : set (sigma σ)} : is_open s ↔ ∀ i, is_open (sigma.mk i ⁻¹' s)
by simp only [is_open_supr_iff, is_open_coinduced]
lemma
is_open_sigma_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_open", "is_open_coinduced", "is_open_supr_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_closed_sigma_iff {s : set (sigma σ)} : is_closed s ↔ ∀ i, is_closed (sigma.mk i ⁻¹' s)
by simp only [← is_open_compl_iff, is_open_sigma_iff, preimage_compl]
lemma
is_closed_sigma_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_closed", "is_open_compl_iff", "is_open_sigma_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_map_sigma_mk {i : ι} : is_open_map (@sigma.mk ι σ i)
begin intros s hs, rw is_open_sigma_iff, intro j, rcases eq_or_ne j i with (rfl|hne), { rwa set.preimage_image_eq _ sigma_mk_injective }, { rw [preimage_image_sigma_mk_of_ne hne], exact is_open_empty } end
lemma
is_open_map_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "eq_or_ne", "is_open_empty", "is_open_map", "is_open_sigma_iff", "set.preimage_image_eq", "sigma_mk_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_range_sigma_mk {i : ι} : is_open (set.range (@sigma.mk ι σ i))
is_open_map_sigma_mk.is_open_range
lemma
is_open_range_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_open", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_closed_map_sigma_mk {i : ι} : is_closed_map (@sigma.mk ι σ i)
begin intros s hs, rw is_closed_sigma_iff, intro j, rcases eq_or_ne j i with (rfl|hne), { rwa set.preimage_image_eq _ sigma_mk_injective }, { rw [preimage_image_sigma_mk_of_ne hne], exact is_closed_empty } end
lemma
is_closed_map_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "eq_or_ne", "is_closed_empty", "is_closed_map", "is_closed_sigma_iff", "set.preimage_image_eq", "sigma_mk_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_closed_range_sigma_mk {i : ι} : is_closed (set.range (@sigma.mk ι σ i))
is_closed_map_sigma_mk.closed_range
lemma
is_closed_range_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_closed", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_embedding_sigma_mk {i : ι} : open_embedding (@sigma.mk ι σ i)
open_embedding_of_continuous_injective_open continuous_sigma_mk sigma_mk_injective is_open_map_sigma_mk
lemma
open_embedding_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous_sigma_mk", "is_open_map_sigma_mk", "open_embedding", "open_embedding_of_continuous_injective_open", "sigma_mk_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closed_embedding_sigma_mk {i : ι} : closed_embedding (@sigma.mk ι σ i)
closed_embedding_of_continuous_injective_closed continuous_sigma_mk sigma_mk_injective is_closed_map_sigma_mk
lemma
closed_embedding_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "closed_embedding", "closed_embedding_of_continuous_injective_closed", "continuous_sigma_mk", "is_closed_map_sigma_mk", "sigma_mk_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
embedding_sigma_mk {i : ι} : embedding (@sigma.mk ι σ i)
closed_embedding_sigma_mk.1
lemma
embedding_sigma_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "embedding" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sigma.nhds_mk (i : ι) (x : σ i) : 𝓝 (⟨i, x⟩ : sigma σ) = map (sigma.mk i) (𝓝 x)
(open_embedding_sigma_mk.map_nhds_eq x).symm
lemma
sigma.nhds_mk
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sigma.nhds_eq (x : sigma σ) : 𝓝 x = map (sigma.mk x.1) (𝓝 x.2)
by { cases x, apply sigma.nhds_mk }
lemma
sigma.nhds_eq
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "sigma.nhds_mk" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_sigma_mk_nhds (i : ι) (x : σ i) : comap (sigma.mk i) (𝓝 ⟨i, x⟩) = 𝓝 x
(embedding_sigma_mk.to_inducing.nhds_eq_comap _).symm
lemma
comap_sigma_mk_nhds
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_sigma_fst_preimage (s : set ι) : is_open (sigma.fst ⁻¹' s : set (Σ a, σ a))
begin rw [← bUnion_of_singleton s, preimage_Union₂], simp only [← range_sigma_mk], exact is_open_bUnion (λ _ _, is_open_range_sigma_mk) end
lemma
is_open_sigma_fst_preimage
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_open", "is_open_bUnion", "is_open_range_sigma_mk" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_sigma_iff {f : sigma σ → α} : continuous f ↔ ∀ i, continuous (λ a, f ⟨i, a⟩)
by simp only [continuous_supr_dom, continuous_coinduced_dom]
lemma
continuous_sigma_iff
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_coinduced_dom", "continuous_supr_dom" ]
A map out of a sum type is continuous iff its restriction to each summand is.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_sigma {f : sigma σ → α} (hf : ∀ i, continuous (λ a, f ⟨i, a⟩)) : continuous f
continuous_sigma_iff.2 hf
lemma
continuous_sigma
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous" ]
A map out of a sum type is continuous if its restriction to each summand is.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} : continuous (sigma.map f₁ f₂) ↔ ∀ i, continuous (f₂ i)
continuous_sigma_iff.trans $ by simp only [sigma.map, embedding_sigma_mk.continuous_iff]
lemma
continuous_sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "sigma.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} (hf : ∀ i, continuous (f₂ i)) : continuous (sigma.map f₁ f₂)
continuous_sigma_map.2 hf
lemma
continuous.sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "sigma.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_map_sigma {f : sigma σ → α} : is_open_map f ↔ ∀ i, is_open_map (λ a, f ⟨i, a⟩)
by simp only [is_open_map_iff_nhds_le, sigma.forall, sigma.nhds_eq, map_map]
lemma
is_open_map_sigma
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_open_map", "is_open_map_iff_nhds_le", "sigma.nhds_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_map_sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} : is_open_map (sigma.map f₁ f₂) ↔ ∀ i, is_open_map (f₂ i)
is_open_map_sigma.trans $ forall_congr $ λ i, (@open_embedding_sigma_mk _ _ _ (f₁ i)).is_open_map_iff.symm
lemma
is_open_map_sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "is_open_map", "open_embedding_sigma_mk", "sigma.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inducing_sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} (h₁ : injective f₁) : inducing (sigma.map f₁ f₂) ↔ ∀ i, inducing (f₂ i)
by simp only [inducing_iff_nhds, sigma.forall, sigma.nhds_mk, sigma.map, ← map_sigma_mk_comap h₁, map_inj sigma_mk_injective]
lemma
inducing_sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "inducing", "inducing_iff_nhds", "sigma.map", "sigma.nhds_mk", "sigma_mk_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
embedding_sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} (h : injective f₁) : embedding (sigma.map f₁ f₂) ↔ ∀ i, embedding (f₂ i)
by simp only [embedding_iff, injective.sigma_map, inducing_sigma_map h, forall_and_distrib, h.sigma_map_iff]
lemma
embedding_sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "embedding", "forall_and_distrib", "inducing_sigma_map", "sigma.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_embedding_sigma_map {f₁ : ι → κ} {f₂ : Π i, σ i → τ (f₁ i)} (h : injective f₁) : open_embedding (sigma.map f₁ f₂) ↔ ∀ i, open_embedding (f₂ i)
by simp only [open_embedding_iff_embedding_open, is_open_map_sigma_map, embedding_sigma_map h, forall_and_distrib]
lemma
open_embedding_sigma_map
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "embedding_sigma_map", "forall_and_distrib", "is_open_map_sigma_map", "open_embedding", "open_embedding_iff_embedding_open", "sigma.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_ulift_down [topological_space α] : continuous (ulift.down : ulift.{v u} α → α)
continuous_induced_dom
lemma
continuous_ulift_down
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_induced_dom", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_ulift_up [topological_space α] : continuous (ulift.up : α → ulift.{v u} α)
continuous_induced_rng.2 continuous_id
lemma
continuous_ulift_up
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "continuous", "continuous_id", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
embedding_ulift_down [topological_space α] : embedding (ulift.down : ulift.{v u} α → α)
⟨⟨rfl⟩, ulift.down_injective⟩
lemma
embedding_ulift_down
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "embedding", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ulift.closed_embedding_down [topological_space α] : closed_embedding (ulift.down : ulift.{v u} α → α)
⟨embedding_ulift_down, by simp only [ulift.down_surjective.range_eq, is_closed_univ]⟩
lemma
ulift.closed_embedding_down
topology
src/topology/constructions.lean
[ "topology.maps", "order.filter.pi" ]
[ "closed_embedding", "is_closed_univ", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_bind_nhds_within {a : α} {s : set α} : (𝓝 a).bind (λ x, 𝓝[s] x) = 𝓝[s] a
bind_inf_principal.trans $ congr_arg2 _ nhds_bind_nhds rfl
lemma
nhds_bind_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "congr_arg2", "nhds_bind_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eventually_nhds_nhds_within {a : α} {s : set α} {p : α → Prop} : (∀ᶠ y in 𝓝 a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x
filter.ext_iff.1 nhds_bind_nhds_within {x | p x}
lemma
eventually_nhds_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds_bind_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eventually_nhds_within_iff {a : α} {s : set α} {p : α → Prop} : (∀ᶠ x in 𝓝[s] a, p x) ↔ ∀ᶠ x in 𝓝 a, x ∈ s → p x
eventually_inf_principal
lemma
eventually_nhds_within_iff
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
frequently_nhds_within_iff {z : α} {s : set α} {p : α → Prop} : (∃ᶠ x in 𝓝[s] z, p x) ↔ (∃ᶠ x in 𝓝 z, p x ∧ x ∈ s)
iff.not (by simp [eventually_nhds_within_iff, not_and'])
lemma
frequently_nhds_within_iff
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "eventually_nhds_within_iff", "iff.not", "not_and'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_closure_ne_iff_frequently_within {z : α} {s : set α} : z ∈ closure (s \ {z}) ↔ ∃ᶠ x in 𝓝[≠] z, x ∈ s
by simp [mem_closure_iff_frequently, frequently_nhds_within_iff]
lemma
mem_closure_ne_iff_frequently_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "closure", "frequently_nhds_within_iff", "mem_closure_iff_frequently" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eventually_nhds_within_nhds_within {a : α} {s : set α} {p : α → Prop} : (∀ᶠ y in 𝓝[s] a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x
begin refine ⟨λ h, _, λ h, (eventually_nhds_nhds_within.2 h).filter_mono inf_le_left⟩, simp only [eventually_nhds_within_iff] at h ⊢, exact h.mono (λ x hx hxs, (hx hxs).self_of_nhds hxs) end
lemma
eventually_nhds_within_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "eventually_nhds_within_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_eq (a : α) (s : set α) : 𝓝[s] a = ⨅ t ∈ {t : set α | a ∈ t ∧ is_open t}, 𝓟 (t ∩ s)
((nhds_basis_opens a).inf_principal s).eq_binfi
theorem
nhds_within_eq
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "is_open", "nhds_basis_opens" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_univ (a : α) : 𝓝[set.univ] a = 𝓝 a
by rw [nhds_within, principal_univ, inf_top_eq]
theorem
nhds_within_univ
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "inf_top_eq", "nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_has_basis {p : β → Prop} {s : β → set α} {a : α} (h : (𝓝 a).has_basis p s) (t : set α) : (𝓝[t] a).has_basis p (λ i, s i ∩ t)
h.inf_principal t
lemma
nhds_within_has_basis
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_basis_open (a : α) (t : set α) : (𝓝[t] a).has_basis (λ u, a ∈ u ∧ is_open u) (λ u, u ∩ t)
nhds_within_has_basis (nhds_basis_opens a) t
lemma
nhds_within_basis_open
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "is_open", "nhds_basis_opens", "nhds_within_has_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_within {t : set α} {a : α} {s : set α} : t ∈ 𝓝[s] a ↔ ∃ u, is_open u ∧ a ∈ u ∧ u ∩ s ⊆ t
by simpa only [exists_prop, and_assoc, and_comm] using (nhds_within_basis_open a s).mem_iff
theorem
mem_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "exists_prop", "is_open", "nhds_within_basis_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_within_iff_exists_mem_nhds_inter {t : set α} {a : α} {s : set α} : t ∈ 𝓝[s] a ↔ ∃ u ∈ 𝓝 a, u ∩ s ⊆ t
(nhds_within_has_basis (𝓝 a).basis_sets s).mem_iff
lemma
mem_nhds_within_iff_exists_mem_nhds_inter
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds_within_has_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diff_mem_nhds_within_compl {x : α} {s : set α} (hs : s ∈ 𝓝 x) (t : set α) : s \ t ∈ 𝓝[tᶜ] x
diff_mem_inf_principal_compl hs t
lemma
diff_mem_nhds_within_compl
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diff_mem_nhds_within_diff {x : α} {s t : set α} (hs : s ∈ 𝓝[t] x) (t' : set α) : s \ t' ∈ 𝓝[t \ t'] x
begin rw [nhds_within, diff_eq, diff_eq, ← inf_principal, ← inf_assoc], exact inter_mem_inf hs (mem_principal_self _) end
lemma
diff_mem_nhds_within_diff
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "inf_assoc", "nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_of_nhds_within_of_nhds {s t : set α} {a : α} (h1 : s ∈ 𝓝 a) (h2 : t ∈ 𝓝[s] a) : (t ∈ 𝓝 a)
begin rcases mem_nhds_within_iff_exists_mem_nhds_inter.mp h2 with ⟨_, Hw, hw⟩, exact (nhds a).sets_of_superset ((nhds a).inter_sets Hw h1) hw, end
lemma
nhds_of_nhds_within_of_nhds
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_within_iff_eventually {s t : set α} {x : α} : t ∈ 𝓝[s] x ↔ ∀ᶠ y in 𝓝 x, y ∈ s → y ∈ t
set_eventually_le_iff_mem_inf_principal.symm
lemma
mem_nhds_within_iff_eventually
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_within_iff_eventually_eq {s t : set α} {x : α} : t ∈ 𝓝[s] x ↔ s =ᶠ[𝓝 x] (s ∩ t : set α)
by simp_rw [mem_nhds_within_iff_eventually, eventually_eq_set, mem_inter_iff, iff_self_and]
lemma
mem_nhds_within_iff_eventually_eq
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "iff_self_and", "mem_nhds_within_iff_eventually" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_eq_iff_eventually_eq {s t : set α} {x : α} : 𝓝[s] x = 𝓝[t] x ↔ s =ᶠ[𝓝 x] t
set_eventually_eq_iff_inf_principal.symm
lemma
nhds_within_eq_iff_eventually_eq
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_le_iff {s t : set α} {x : α} : 𝓝[s] x ≤ 𝓝[t] x ↔ t ∈ 𝓝[s] x
set_eventually_le_iff_inf_principal_le.symm.trans set_eventually_le_iff_mem_inf_principal
lemma
nhds_within_le_iff
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preimage_nhds_within_coinduced' {π : α → β} {s : set β} {t : set α} {a : α} (h : a ∈ t) (ht : is_open t) (hs : s ∈ @nhds β (topological_space.coinduced (λ x : t, π x) subtype.topological_space) (π a)) : π ⁻¹' s ∈ 𝓝[t] a
begin letI := topological_space.coinduced (λ x : t, π x) subtype.topological_space, rcases mem_nhds_iff.mp hs with ⟨V, hVs, V_op, mem_V⟩, refine mem_nhds_within_iff_exists_mem_nhds_inter.mpr ⟨π ⁻¹' V, mem_nhds_iff.mpr ⟨t ∩ π ⁻¹' V, inter_subset_right t (π ⁻¹' V), _, mem_sep h mem_V⟩, subset.trans (inter_subse...
lemma
preimage_nhds_within_coinduced'
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "is_open", "nhds", "set.inter_comm", "topological_space.coinduced" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_within_of_mem_nhds {s t : set α} {a : α} (h : s ∈ 𝓝 a) : s ∈ 𝓝[t] a
mem_inf_of_left h
lemma
mem_nhds_within_of_mem_nhds
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
self_mem_nhds_within {a : α} {s : set α} : s ∈ 𝓝[s] a
mem_inf_of_right (mem_principal_self s)
theorem
self_mem_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eventually_mem_nhds_within {a : α} {s : set α} : ∀ᶠ x in 𝓝[s] a, x ∈ s
self_mem_nhds_within
theorem
eventually_mem_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "self_mem_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inter_mem_nhds_within (s : set α) {t : set α} {a : α} (h : t ∈ 𝓝 a) : s ∩ t ∈ 𝓝[s] a
inter_mem self_mem_nhds_within (mem_inf_of_left h)
theorem
inter_mem_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "self_mem_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_mono (a : α) {s t : set α} (h : s ⊆ t) : 𝓝[s] a ≤ 𝓝[t] a
inf_le_inf_left _ (principal_mono.mpr h)
theorem
nhds_within_mono
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "inf_le_inf_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pure_le_nhds_within {a : α} {s : set α} (ha : a ∈ s) : pure a ≤ 𝓝[s] a
le_inf (pure_le_nhds a) (le_principal_iff.2 ha)
lemma
pure_le_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "le_inf", "pure_le_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_of_mem_nhds_within {a : α} {s t : set α} (ha : a ∈ s) (ht : t ∈ 𝓝[s] a) : a ∈ t
pure_le_nhds_within ha ht
lemma
mem_of_mem_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "pure_le_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.eventually.self_of_nhds_within {p : α → Prop} {s : set α} {x : α} (h : ∀ᶠ y in 𝓝[s] x, p y) (hx : x ∈ s) : p x
mem_of_mem_nhds_within hx h
lemma
filter.eventually.self_of_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "mem_of_mem_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_const_nhds_within {l : filter β} {s : set α} {a : α} (ha : a ∈ s) : tendsto (λ x : β, a) l (𝓝[s] a)
tendsto_const_pure.mono_right $ pure_le_nhds_within ha
lemma
tendsto_const_nhds_within
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "filter", "pure_le_nhds_within" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_restrict'' {a : α} (s : set α) {t : set α} (h : t ∈ 𝓝[s] a) : 𝓝[s] a = 𝓝[s ∩ t] a
le_antisymm (le_inf inf_le_left (le_principal_iff.mpr (inter_mem self_mem_nhds_within h))) (inf_le_inf_left _ (principal_mono.mpr (set.inter_subset_left _ _)))
theorem
nhds_within_restrict''
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "inf_le_inf_left", "inf_le_left", "le_inf", "self_mem_nhds_within", "set.inter_subset_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_restrict' {a : α} (s : set α) {t : set α} (h : t ∈ 𝓝 a) : 𝓝[s] a = 𝓝[s ∩ t] a
nhds_within_restrict'' s $ mem_inf_of_left h
theorem
nhds_within_restrict'
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds_within_restrict''" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_restrict {a : α} (s : set α) {t : set α} (h₀ : a ∈ t) (h₁ : is_open t) : 𝓝[s] a = 𝓝[s ∩ t] a
nhds_within_restrict' s (is_open.mem_nhds h₁ h₀)
theorem
nhds_within_restrict
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "is_open", "is_open.mem_nhds", "nhds_within_restrict'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_le_of_mem {a : α} {s t : set α} (h : s ∈ 𝓝[t] a) : 𝓝[t] a ≤ 𝓝[s] a
nhds_within_le_iff.mpr h
theorem
nhds_within_le_of_mem
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_le_nhds {a : α} {s : set α} : 𝓝[s] a ≤ 𝓝 a
by { rw ← nhds_within_univ, apply nhds_within_le_of_mem, exact univ_mem }
theorem
nhds_within_le_nhds
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds_within_le_of_mem", "nhds_within_univ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_within_eq_nhds_within' {a : α} {s t u : set α} (hs : s ∈ 𝓝 a) (h₂ : t ∩ s = u ∩ s) : 𝓝[t] a = 𝓝[u] a
by rw [nhds_within_restrict' t hs, nhds_within_restrict' u hs, h₂]
lemma
nhds_within_eq_nhds_within'
topology
src/topology/continuous_on.lean
[ "topology.constructions" ]
[ "nhds_within_restrict'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83