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lift_cover_restrict' {s : set α} {hs : s ∈ A} : (lift_cover' A F hF hA).restrict s = F s hs
ext $ lift_cover_coe'
lemma
continuous_map.lift_cover_restrict'
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_continuous_map (e : α ≃ₜ β) : C(α, β)
⟨e⟩
def
homeomorph.to_continuous_map
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[]
The forward direction of a homeomorphism, as a bundled continuous map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_continuous_map_as_coe : f.to_continuous_map = f
rfl
lemma
homeomorph.to_continuous_map_as_coe
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_refl : (homeomorph.refl α : C(α, α)) = continuous_map.id α
rfl
lemma
homeomorph.coe_refl
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[ "continuous_map.id", "homeomorph.refl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_trans : (f.trans g : C(α, γ)) = (g : C(β, γ)).comp f
rfl
lemma
homeomorph.coe_trans
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm_comp_to_continuous_map : (f.symm : C(β, α)).comp (f : C(α, β)) = continuous_map.id α
by rw [← coe_trans, self_trans_symm, coe_refl]
lemma
homeomorph.symm_comp_to_continuous_map
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[ "continuous_map.id" ]
Left inverse to a continuous map from a homeomorphism, mirroring `equiv.symm_comp_self`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_continuous_map_comp_symm : (f : C(α, β)).comp (f.symm : C(β, α)) = continuous_map.id β
by rw [← coe_trans, symm_trans_self, coe_refl]
lemma
homeomorph.to_continuous_map_comp_symm
topology.continuous_function
src/topology/continuous_function/basic.lean
[ "data.set.Union_lift", "topology.homeomorph" ]
[ "continuous_map.id" ]
Right inverse to a continuous map from a homeomorphism, mirroring `equiv.self_comp_symm`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_continuous_function (α : Type u) (β : Type v) [topological_space α] [pseudo_metric_space β] extends continuous_map α β : Type (max u v)
(map_bounded' : ∃ C, ∀ x y, dist (to_fun x) (to_fun y) ≤ C)
structure
bounded_continuous_function
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous_map", "pseudo_metric_space", "topological_space" ]
`α →ᵇ β` is the type of bounded continuous functions `α → β` from a topological space to a metric space. When possible, instead of parametrizing results over `(f : α →ᵇ β)`, you should parametrize over `(F : Type*) [bounded_continuous_map_class F α β] (f : F)`. When you extend this structure, make sure to extend `bou...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_continuous_map_class (F α β : Type*) [topological_space α] [pseudo_metric_space β] extends continuous_map_class F α β
(map_bounded (f : F) : ∃ C, ∀ x y, dist (f x) (f y) ≤ C)
class
bounded_continuous_map_class
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous_map_class", "pseudo_metric_space", "topological_space" ]
`bounded_continuous_map_class F α β` states that `F` is a type of bounded continuous maps. You should also extend this typeclass when you extend `bounded_continuous_function`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_to_continuous_fun (f : α →ᵇ β) : (f.to_continuous_map : α → β) = f
rfl
lemma
bounded_continuous_function.coe_to_continuous_fun
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simps.apply (h : α →ᵇ β) : α → β
h initialize_simps_projections bounded_continuous_function (to_continuous_map_to_fun → apply)
def
bounded_continuous_function.simps.apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "bounded_continuous_function" ]
See Note [custom simps projection]. We need to specify this projection explicitly in this case, because it is a composition of multiple projections.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded (f : α →ᵇ β) : ∃C, ∀ x y : α, dist (f x) (f y) ≤ C
f.map_bounded'
lemma
bounded_continuous_function.bounded
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous (f : α →ᵇ β) : continuous f
f.to_continuous_map.continuous
lemma
bounded_continuous_function.continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext (h : ∀ x, f x = g x) : f = g
fun_like.ext _ _ h
lemma
bounded_continuous_function.ext
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "fun_like.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_range (f : α →ᵇ β) : bounded (range f)
bounded_range_iff.2 f.bounded
lemma
bounded_continuous_function.bounded_range
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_image (f : α →ᵇ β) (s : set α) : bounded (f '' s)
f.bounded_range.mono $ image_subset_range _ _
lemma
bounded_continuous_function.bounded_image
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_of_empty [is_empty α] (f g : α →ᵇ β) : f = g
ext $ is_empty.elim ‹_›
lemma
bounded_continuous_function.eq_of_empty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "is_empty", "is_empty.elim" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_bound (f : C(α, β)) (C : ℝ) (h : ∀ x y : α, dist (f x) (f y) ≤ C) : α →ᵇ β
⟨f, ⟨C, h⟩⟩
def
bounded_continuous_function.mk_of_bound
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
A continuous function with an explicit bound is a bounded continuous function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_bound_coe {f} {C} {h} : (mk_of_bound f C h : α → β) = (f : α → β)
rfl
lemma
bounded_continuous_function.mk_of_bound_coe
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_compact [compact_space α] (f : C(α, β)) : α →ᵇ β
⟨f, bounded_range_iff.1 (is_compact_range f.continuous).bounded⟩
def
bounded_continuous_function.mk_of_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space", "is_compact_range" ]
A continuous function on a compact space is automatically a bounded continuous function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_compact_apply [compact_space α] (f : C(α, β)) (a : α) : mk_of_compact f a = f a
rfl
lemma
bounded_continuous_function.mk_of_compact_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_discrete [discrete_topology α] (f : α → β) (C : ℝ) (h : ∀ x y : α, dist (f x) (f y) ≤ C) : α →ᵇ β
⟨⟨f, continuous_of_discrete_topology⟩, ⟨C, h⟩⟩
def
bounded_continuous_function.mk_of_discrete
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "discrete_topology" ]
If a function is bounded on a discrete space, it is automatically continuous, and therefore gives rise to an element of the type of bounded continuous functions
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_eq : dist f g = Inf {C | 0 ≤ C ∧ ∀ x : α, dist (f x) (g x) ≤ C}
rfl
lemma
bounded_continuous_function.dist_eq
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_set_exists : ∃ C, 0 ≤ C ∧ ∀ x : α, dist (f x) (g x) ≤ C
begin rcases f.bounded_range.union g.bounded_range with ⟨C, hC⟩, refine ⟨max 0 C, le_max_left _ _, λ x, (hC _ _ _ _).trans (le_max_right _ _)⟩; [left, right]; apply mem_range_self end
lemma
bounded_continuous_function.dist_set_exists
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_coe_le_dist (x : α) : dist (f x) (g x) ≤ dist f g
le_cInf dist_set_exists $ λb hb, hb.2 x
lemma
bounded_continuous_function.dist_coe_le_dist
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "le_cInf" ]
The pointwise distance is controlled by the distance between functions, by definition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_nonneg' : 0 ≤ dist f g
le_cInf dist_set_exists (λ C, and.left)
lemma
bounded_continuous_function.dist_nonneg'
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "le_cInf" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_le (C0 : (0 : ℝ) ≤ C) : dist f g ≤ C ↔ ∀x:α, dist (f x) (g x) ≤ C
⟨λ h x, le_trans (dist_coe_le_dist x) h, λ H, cInf_le ⟨0, λ C, and.left⟩ ⟨C0, H⟩⟩
lemma
bounded_continuous_function.dist_le
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "cInf_le" ]
The distance between two functions is controlled by the supremum of the pointwise distances
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_le_iff_of_nonempty [nonempty α] : dist f g ≤ C ↔ ∀ x, dist (f x) (g x) ≤ C
⟨λ h x, le_trans (dist_coe_le_dist x) h, λ w, (dist_le (le_trans dist_nonneg (w (nonempty.some ‹_›)))).mpr w⟩
lemma
bounded_continuous_function.dist_le_iff_of_nonempty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "nonempty.some" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_lt_of_nonempty_compact [nonempty α] [compact_space α] (w : ∀x:α, dist (f x) (g x) < C) : dist f g < C
begin have c : continuous (λ x, dist (f x) (g x)), { continuity, }, obtain ⟨x, -, le⟩ := is_compact.exists_forall_ge is_compact_univ set.univ_nonempty (continuous.continuous_on c), exact lt_of_le_of_lt (dist_le_iff_of_nonempty.mpr (λ y, le y trivial)) (w x), end
lemma
bounded_continuous_function.dist_lt_of_nonempty_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space", "continuity", "continuous", "continuous.continuous_on", "is_compact.exists_forall_ge", "is_compact_univ", "set.univ_nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_lt_iff_of_compact [compact_space α] (C0 : (0 : ℝ) < C) : dist f g < C ↔ ∀x:α, dist (f x) (g x) < C
begin fsplit, { intros w x, exact lt_of_le_of_lt (dist_coe_le_dist x) w, }, { by_cases h : nonempty α, { resetI, exact dist_lt_of_nonempty_compact, }, { rintro -, convert C0, apply le_antisymm _ dist_nonneg', rw [dist_eq], exact cInf_le ⟨0, λ C, and.left⟩ ⟨le_rfl, λ x, fa...
lemma
bounded_continuous_function.dist_lt_iff_of_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "cInf_le", "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_lt_iff_of_nonempty_compact [nonempty α] [compact_space α] : dist f g < C ↔ ∀x:α, dist (f x) (g x) < C
⟨λ w x, lt_of_le_of_lt (dist_coe_le_dist x) w, dist_lt_of_nonempty_compact⟩
lemma
bounded_continuous_function.dist_lt_iff_of_nonempty_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nndist_eq : nndist f g = Inf {C | ∀ x : α, nndist (f x) (g x) ≤ C}
subtype.ext $ dist_eq.trans $ begin rw [nnreal.coe_Inf, nnreal.coe_image], simp_rw [mem_set_of_eq, ←nnreal.coe_le_coe, subtype.coe_mk, exists_prop, coe_nndist], end
lemma
bounded_continuous_function.nndist_eq
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "coe_nndist", "exists_prop", "nnreal.coe_Inf", "nnreal.coe_image", "subtype.coe_mk", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nndist_set_exists : ∃ C, ∀ x : α, nndist (f x) (g x) ≤ C
subtype.exists.mpr $ dist_set_exists.imp $ λ a ⟨ha, h⟩, ⟨ha, h⟩
lemma
bounded_continuous_function.nndist_set_exists
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nndist_coe_le_nndist (x : α) : nndist (f x) (g x) ≤ nndist f g
dist_coe_le_dist x
lemma
bounded_continuous_function.nndist_coe_le_nndist
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_zero_of_empty [is_empty α] : dist f g = 0
by rw [(ext is_empty_elim : f = g), dist_self]
lemma
bounded_continuous_function.dist_zero_of_empty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_self", "is_empty", "is_empty_elim" ]
On an empty space, bounded continuous functions are at distance 0
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_eq_supr : dist f g = ⨆ x : α, dist (f x) (g x)
begin casesI is_empty_or_nonempty α, { rw [supr_of_empty', real.Sup_empty, dist_zero_of_empty] }, refine (dist_le_iff_of_nonempty.mpr $ le_csupr _).antisymm (csupr_le dist_coe_le_dist), exact dist_set_exists.imp (λ C hC, forall_range_iff.2 hC.2) end
lemma
bounded_continuous_function.dist_eq_supr
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "csupr_le", "is_empty_or_nonempty", "le_csupr", "real.Sup_empty", "supr_of_empty'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nndist_eq_supr : nndist f g = ⨆ x : α, nndist (f x) (g x)
subtype.ext $ dist_eq_supr.trans $ by simp_rw [nnreal.coe_supr, coe_nndist]
lemma
bounded_continuous_function.nndist_eq_supr
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "coe_nndist", "nnreal.coe_supr", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_iff_tendsto_uniformly {ι : Type*} {F : ι → (α →ᵇ β)} {f : α →ᵇ β} {l : filter ι} : tendsto F l (𝓝 f) ↔ tendsto_uniformly (λ i, F i) f l
iff.intro (λ h, tendsto_uniformly_iff.2 (λ ε ε0, (metric.tendsto_nhds.mp h ε ε0).mp (eventually_of_forall $ λ n hn x, lt_of_le_of_lt (dist_coe_le_dist x) (dist_comm (F n) f ▸ hn)))) (λ h, metric.tendsto_nhds.mpr $ λ ε ε_pos, (h _ (dist_mem_uniformity $ half_pos ε_pos)).mp (eventually_of_forall $ λ n...
lemma
bounded_continuous_function.tendsto_iff_tendsto_uniformly
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_comm", "filter", "half_pos", "tendsto_uniformly" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inducing_coe_fn : inducing (uniform_fun.of_fun ∘ coe_fn : (α →ᵇ β) → (α →ᵤ β))
begin rw inducing_iff_nhds, refine λ f, eq_of_forall_le_iff (λ l, _), rw [← tendsto_iff_comap, ← tendsto_id', tendsto_iff_tendsto_uniformly, uniform_fun.tendsto_iff_tendsto_uniformly], refl end
lemma
bounded_continuous_function.inducing_coe_fn
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "eq_of_forall_le_iff", "inducing", "inducing_iff_nhds", "uniform_fun.of_fun", "uniform_fun.tendsto_iff_tendsto_uniformly" ]
The topology on `α →ᵇ β` is exactly the topology induced by the natural map to `α →ᵤ β`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
embedding_coe_fn : embedding (uniform_fun.of_fun ∘ coe_fn : (α →ᵇ β) → (α →ᵤ β))
⟨inducing_coe_fn, λ f g h, ext $ λ x, congr_fun h x⟩
lemma
bounded_continuous_function.embedding_coe_fn
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "embedding", "uniform_fun.of_fun" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const (b : β) : α →ᵇ β
⟨continuous_map.const α b, 0, by simp [le_rfl]⟩
def
bounded_continuous_function.const
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "le_rfl" ]
Constant as a continuous bounded function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_apply' (a : α) (b : β) : (const α b : α → β) a = b
rfl
lemma
bounded_continuous_function.const_apply'
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_evalx (x : α) : lipschitz_with 1 (λ f : α →ᵇ β, f x)
lipschitz_with.mk_one $ λ f g, dist_coe_le_dist x
lemma
bounded_continuous_function.lipschitz_evalx
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "lipschitz_with", "lipschitz_with.mk_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_continuous_coe : @uniform_continuous (α →ᵇ β) (α → β) _ _ coe_fn
uniform_continuous_pi.2 $ λ x, (lipschitz_evalx x).uniform_continuous
theorem
bounded_continuous_function.uniform_continuous_coe
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "uniform_continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_coe : continuous (λ (f : α →ᵇ β) x, f x)
uniform_continuous.continuous uniform_continuous_coe
lemma
bounded_continuous_function.continuous_coe
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "uniform_continuous.continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_eval_const {x : α} : continuous (λ f : α →ᵇ β, f x)
(continuous_apply x).comp continuous_coe
theorem
bounded_continuous_function.continuous_eval_const
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "continuous_apply" ]
When `x` is fixed, `(f : α →ᵇ β) ↦ f x` is continuous
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_eval : continuous (λ p : (α →ᵇ β) × α, p.1 p.2)
continuous_prod_of_continuous_lipschitz _ 1 (λ f, f.continuous) $ lipschitz_evalx
theorem
bounded_continuous_function.continuous_eval
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "continuous_prod_of_continuous_lipschitz" ]
The evaluation map is continuous, as a joint function of `u` and `x`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_continuous {δ : Type*} [topological_space δ] (f : α →ᵇ β) (g : C(δ, α)) : δ →ᵇ β
{ to_continuous_map := f.1.comp g, map_bounded' := f.map_bounded'.imp (λ C hC x y, hC _ _) }
def
bounded_continuous_function.comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "topological_space" ]
Composition of a bounded continuous function and a continuous function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_comp_continuous {δ : Type*} [topological_space δ] (f : α →ᵇ β) (g : C(δ, α)) : coe_fn (f.comp_continuous g) = f ∘ g
rfl
lemma
bounded_continuous_function.coe_comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_continuous_apply {δ : Type*} [topological_space δ] (f : α →ᵇ β) (g : C(δ, α)) (x : δ) : f.comp_continuous g x = f (g x)
rfl
lemma
bounded_continuous_function.comp_continuous_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_comp_continuous {δ : Type*} [topological_space δ] (g : C(δ, α)) : lipschitz_with 1 (λ f : α →ᵇ β, f.comp_continuous g)
lipschitz_with.mk_one $ λ f₁ f₂, (dist_le dist_nonneg).2 $ λ x, dist_coe_le_dist (g x)
lemma
bounded_continuous_function.lipschitz_comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "lipschitz_with", "lipschitz_with.mk_one", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_comp_continuous {δ : Type*} [topological_space δ] (g : C(δ, α)) : continuous (λ f : α →ᵇ β, f.comp_continuous g)
(lipschitz_comp_continuous g).continuous
lemma
bounded_continuous_function.continuous_comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict (f : α →ᵇ β) (s : set α) : s →ᵇ β
f.comp_continuous $ (continuous_map.id _).restrict s
def
bounded_continuous_function.restrict
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous_map.id" ]
Restrict a bounded continuous function to a set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict (f : α →ᵇ β) (s : set α) : coe_fn (f.restrict s) = f ∘ coe
rfl
lemma
bounded_continuous_function.coe_restrict
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_apply (f : α →ᵇ β) (s : set α) (x : s) : f.restrict s x = f x
rfl
lemma
bounded_continuous_function.restrict_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp (G : β → γ) {C : ℝ≥0} (H : lipschitz_with C G) (f : α →ᵇ β) : α →ᵇ γ
⟨⟨λx, G (f x), H.continuous.comp f.continuous⟩, let ⟨D, hD⟩ := f.bounded in ⟨max C 0 * D, λ x y, calc dist (G (f x)) (G (f y)) ≤ C * dist (f x) (f y) : H.dist_le_mul _ _ ... ≤ max C 0 * dist (f x) (f y) : mul_le_mul_of_nonneg_right (le_max_left C 0) dist_nonneg ... ≤ max C 0 * D : mul_le_mul_of_nonneg_l...
def
bounded_continuous_function.comp
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "lipschitz_with", "mul_le_mul_of_nonneg_left", "mul_le_mul_of_nonneg_right" ]
Composition (in the target) of a bounded continuous function with a Lipschitz map again gives a bounded continuous function
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lipschitz_comp {G : β → γ} {C : ℝ≥0} (H : lipschitz_with C G) : lipschitz_with C (comp G H : (α →ᵇ β) → α →ᵇ γ)
lipschitz_with.of_dist_le_mul $ λ f g, (dist_le (mul_nonneg C.2 dist_nonneg)).2 $ λ x, calc dist (G (f x)) (G (g x)) ≤ C * dist (f x) (g x) : H.dist_le_mul _ _ ... ≤ C * dist f g : mul_le_mul_of_nonneg_left (dist_coe_le_dist _) C.2
lemma
bounded_continuous_function.lipschitz_comp
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "lipschitz_with", "mul_le_mul_of_nonneg_left" ]
The composition operator (in the target) with a Lipschitz map is Lipschitz
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_continuous_comp {G : β → γ} {C : ℝ≥0} (H : lipschitz_with C G) : uniform_continuous (comp G H : (α →ᵇ β) → α →ᵇ γ)
(lipschitz_comp H).uniform_continuous
lemma
bounded_continuous_function.uniform_continuous_comp
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "lipschitz_with", "uniform_continuous" ]
The composition operator (in the target) with a Lipschitz map is uniformly continuous
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_comp {G : β → γ} {C : ℝ≥0} (H : lipschitz_with C G) : continuous (comp G H : (α →ᵇ β) → α →ᵇ γ)
(lipschitz_comp H).continuous
lemma
bounded_continuous_function.continuous_comp
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "lipschitz_with" ]
The composition operator (in the target) with a Lipschitz map is continuous
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cod_restrict (s : set β) (f : α →ᵇ β) (H : ∀x, f x ∈ s) : α →ᵇ s
⟨⟨s.cod_restrict f H, f.continuous.subtype_mk _⟩, f.bounded⟩
def
bounded_continuous_function.cod_restrict
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
Restriction (in the target) of a bounded continuous function taking values in a subset
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extend (f : α ↪ δ) (g : α →ᵇ β) (h : δ →ᵇ β) : δ →ᵇ β
{ to_fun := extend f g h, continuous_to_fun := continuous_of_discrete_topology, map_bounded' := begin rw [← bounded_range_iff, range_extend f.injective, metric.bounded_union], exact ⟨g.bounded_range, h.bounded_image _⟩ end }
def
bounded_continuous_function.extend
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous_of_discrete_topology", "extend", "metric.bounded_union" ]
A version of `function.extend` for bounded continuous maps. We assume that the domain has discrete topology, so we only need to verify boundedness.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extend_apply (f : α ↪ δ) (g : α →ᵇ β) (h : δ →ᵇ β) (x : α) : extend f g h (f x) = g x
f.injective.extend_apply _ _ _
lemma
bounded_continuous_function.extend_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "extend" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extend_comp (f : α ↪ δ) (g : α →ᵇ β) (h : δ →ᵇ β) : extend f g h ∘ f = g
extend_comp f.injective _ _
lemma
bounded_continuous_function.extend_comp
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "extend", "extend_comp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extend_apply' {f : α ↪ δ} {x : δ} (hx : x ∉ range f) (g : α →ᵇ β) (h : δ →ᵇ β) : extend f g h x = h x
extend_apply' _ _ _ hx
lemma
bounded_continuous_function.extend_apply'
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "extend", "extend_apply'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extend_of_empty [is_empty α] (f : α ↪ δ) (g : α →ᵇ β) (h : δ →ᵇ β) : extend f g h = h
fun_like.coe_injective $ function.extend_of_empty f g h
lemma
bounded_continuous_function.extend_of_empty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "extend", "fun_like.coe_injective", "function.extend_of_empty", "is_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_extend_extend (f : α ↪ δ) (g₁ g₂ : α →ᵇ β) (h₁ h₂ : δ →ᵇ β) : dist (g₁.extend f h₁) (g₂.extend f h₂) = max (dist g₁ g₂) (dist (h₁.restrict (range f)ᶜ) (h₂.restrict (range f)ᶜ))
begin refine le_antisymm ((dist_le $ le_max_iff.2 $ or.inl dist_nonneg).2 $ λ x, _) (max_le _ _), { rcases em (∃ y, f y = x) with (⟨x, rfl⟩|hx), { simp only [extend_apply], exact (dist_coe_le_dist x).trans (le_max_left _ _) }, { simp only [extend_apply' hx], lift x to ((range f)ᶜ : set δ) using ...
lemma
bounded_continuous_function.dist_extend_extend
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "em", "extend", "extend_apply'", "lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
isometry_extend (f : α ↪ δ) (h : δ →ᵇ β) : isometry (λ g : α →ᵇ β, extend f g h)
isometry.of_dist_eq $ λ g₁ g₂, by simp [dist_nonneg]
lemma
bounded_continuous_function.isometry_extend
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "dist_nonneg", "extend", "isometry" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arzela_ascoli₁ [compact_space β] (A : set (α →ᵇ β)) (closed : is_closed A) (H : equicontinuous (coe_fn : A → α → β)) : is_compact A
begin simp_rw [equicontinuous, metric.equicontinuous_at_iff_pair] at H, refine is_compact_of_totally_bounded_is_closed _ closed, refine totally_bounded_of_finite_discretization (λ ε ε0, _), rcases exists_between ε0 with ⟨ε₁, ε₁0, εε₁⟩, let ε₂ := ε₁/2/2, /- We have to find a finite discretization of `u`, i.e...
theorem
bounded_continuous_function.arzela_ascoli₁
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "add_halves", "compact_space", "dist_triangle4_right", "dist_triangle_right", "equicontinuous", "exists_between", "finite_cover_balls_of_compact", "half_pos", "is_closed", "is_compact", "is_compact_of_totally_bounded_is_closed", "is_compact_univ", "is_open", "metric.equicontinuous_at_iff_p...
First version, with pointwise equicontinuity and range in a compact space
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arzela_ascoli₂ (s : set β) (hs : is_compact s) (A : set (α →ᵇ β)) (closed : is_closed A) (in_s : ∀(f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s) (H : equicontinuous (coe_fn : A → α → β)) : is_compact A
/- This version is deduced from the previous one by restricting to the compact type in the target, using compactness there and then lifting everything to the original space. -/ begin have M : lipschitz_with 1 coe := lipschitz_with.subtype_coe s, let F : (α →ᵇ s) → α →ᵇ β := comp coe M, refine is_compact_of_is_clo...
theorem
bounded_continuous_function.arzela_ascoli₂
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space", "equicontinuous", "is_closed", "is_compact", "is_compact_of_is_closed_subset", "lipschitz_with", "lipschitz_with.subtype_coe" ]
Second version, with pointwise equicontinuity and range in a compact subset
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
arzela_ascoli [t2_space β] (s : set β) (hs : is_compact s) (A : set (α →ᵇ β)) (in_s : ∀(f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s) (H : equicontinuous (coe_fn : A → α → β)) : is_compact (closure A)
/- This version is deduced from the previous one by checking that the closure of A, in addition to being closed, still satisfies the properties of compact range and equicontinuity -/ arzela_ascoli₂ s hs (closure A) is_closed_closure (λ f x hf, (mem_of_closed' hs.is_closed).2 $ λ ε ε0, let ⟨g, gA, dist_fg⟩ := metr...
theorem
bounded_continuous_function.arzela_ascoli
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "closure", "equicontinuous", "is_closed_closure", "is_compact", "t2_space" ]
Third (main) version, with pointwise equicontinuity and range in a compact subset, but without closedness. The closure is then compact
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_one : ((1 : α →ᵇ β) : α → β) = 1
rfl
lemma
bounded_continuous_function.coe_one
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_compact_one [compact_space α] : mk_of_compact (1 : C(α, β)) = 1
rfl
lemma
bounded_continuous_function.mk_of_compact_one
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
forall_coe_one_iff_one (f : α →ᵇ β) : (∀ x, f x = 1) ↔ f = 1
(@fun_like.ext_iff _ _ _ _ f 1).symm
lemma
bounded_continuous_function.forall_coe_one_iff_one
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "fun_like.ext_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_comp_continuous [topological_space γ] (f : C(γ, α)) : (1 : α →ᵇ β).comp_continuous f = 1
rfl
lemma
bounded_continuous_function.one_comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_add : ⇑(f + g) = f + g
rfl
lemma
bounded_continuous_function.coe_add
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_apply : (f + g) x = f x + g x
rfl
lemma
bounded_continuous_function.add_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_of_compact_add [compact_space α] (f g : C(α, β)) : mk_of_compact (f + g) = mk_of_compact f + mk_of_compact g
rfl
lemma
bounded_continuous_function.mk_of_compact_add
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_comp_continuous [topological_space γ] (h : C(γ, α)) : (g + f).comp_continuous h = g.comp_continuous h + f.comp_continuous h
rfl
lemma
bounded_continuous_function.add_comp_continuous
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_nsmul_rec : ∀ n, ⇑(nsmul_rec n f) = n • f
| 0 := by rw [nsmul_rec, zero_smul, coe_zero] | (n + 1) := by rw [nsmul_rec, succ_nsmul, coe_add, coe_nsmul_rec]
lemma
bounded_continuous_function.coe_nsmul_rec
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "nsmul_rec", "zero_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_nat_scalar : has_smul ℕ (α →ᵇ β)
{ smul := λ n f, { to_continuous_map := n • f.to_continuous_map, map_bounded' := by simpa [coe_nsmul_rec] using (nsmul_rec n f).map_bounded' } }
instance
bounded_continuous_function.has_nat_scalar
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "has_smul", "nsmul_rec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_nsmul (r : ℕ) (f : α →ᵇ β) : ⇑(r • f) = r • f
rfl
lemma
bounded_continuous_function.coe_nsmul
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nsmul_apply (r : ℕ) (f : α →ᵇ β) (v : α) : (r • f) v = r • f v
rfl
lemma
bounded_continuous_function.nsmul_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_fn_add_hom : (α →ᵇ β) →+ (α → β)
{ to_fun := coe_fn, map_zero' := coe_zero, map_add' := coe_add }
def
bounded_continuous_function.coe_fn_add_hom
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
Coercion of a `normed_add_group_hom` is an `add_monoid_hom`. Similar to `add_monoid_hom.coe_fn`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_continuous_map_add_hom : (α →ᵇ β) →+ C(α, β)
{ to_fun := to_continuous_map, map_zero' := by { ext, simp, }, map_add' := by { intros, ext, simp, }, }
def
bounded_continuous_function.to_continuous_map_add_hom
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
The additive map forgetting that a bounded continuous function is bounded.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_sum {ι : Type*} (s : finset ι) (f : ι → (α →ᵇ β)) : ⇑(∑ i in s, f i) = (∑ i in s, (f i : α → β))
(@coe_fn_add_hom α β _ _ _ _).map_sum f s
lemma
bounded_continuous_function.coe_sum
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "finset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sum_apply {ι : Type*} (s : finset ι) (f : ι → (α →ᵇ β)) (a : α) : (∑ i in s, f i) a = (∑ i in s, f i a)
by simp
lemma
bounded_continuous_function.sum_apply
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "finset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_def : ‖f‖ = dist f 0
rfl
lemma
bounded_continuous_function.norm_def
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq (f : α →ᵇ β) : ‖f‖ = Inf {C : ℝ | 0 ≤ C ∧ ∀ (x : α), ‖f x‖ ≤ C}
by simp [norm_def, bounded_continuous_function.dist_eq]
lemma
bounded_continuous_function.norm_eq
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "bounded_continuous_function.dist_eq" ]
The norm of a bounded continuous function is the supremum of `‖f x‖`. We use `Inf` to ensure that the definition works if `α` has no elements.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq_of_nonempty [h : nonempty α] : ‖f‖ = Inf {C : ℝ | ∀ (x : α), ‖f x‖ ≤ C}
begin unfreezingI { obtain ⟨a⟩ := h, }, rw norm_eq, congr, ext, simp only [and_iff_right_iff_imp], exact λ h', le_trans (norm_nonneg (f a)) (h' a), end
lemma
bounded_continuous_function.norm_eq_of_nonempty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "and_iff_right_iff_imp" ]
When the domain is non-empty, we do not need the `0 ≤ C` condition in the formula for ‖f‖ as an `Inf`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq_zero_of_empty [h : is_empty α] : ‖f‖ = 0
dist_zero_of_empty
lemma
bounded_continuous_function.norm_eq_zero_of_empty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "is_empty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_coe_le_norm (x : α) : ‖f x‖ ≤ ‖f‖
calc ‖f x‖ = dist (f x) ((0 : α →ᵇ β) x) : by simp [dist_zero_right] ... ≤ ‖f‖ : dist_coe_le_dist _
lemma
bounded_continuous_function.norm_coe_le_norm
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_le_two_norm' {f : γ → β} {C : ℝ} (hC : ∀ x, ‖f x‖ ≤ C) (x y : γ) : dist (f x) (f y) ≤ 2 * C
calc dist (f x) (f y) ≤ ‖f x‖ + ‖f y‖ : dist_le_norm_add_norm _ _ ... ≤ C + C : add_le_add (hC x) (hC y) ... = 2 * C : (two_mul _).symm
lemma
bounded_continuous_function.dist_le_two_norm'
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "two_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dist_le_two_norm (x y : α) : dist (f x) (f y) ≤ 2 * ‖f‖
dist_le_two_norm' f.norm_coe_le_norm x y
lemma
bounded_continuous_function.dist_le_two_norm
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
Distance between the images of any two points is at most twice the norm of the function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_le (C0 : (0 : ℝ) ≤ C) : ‖f‖ ≤ C ↔ ∀x:α, ‖f x‖ ≤ C
by simpa using @dist_le _ _ _ _ f 0 _ C0
lemma
bounded_continuous_function.norm_le
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
The norm of a function is controlled by the supremum of the pointwise norms
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_le_of_nonempty [nonempty α] {f : α →ᵇ β} {M : ℝ} : ‖f‖ ≤ M ↔ ∀ x, ‖f x‖ ≤ M
begin simp_rw [norm_def, ←dist_zero_right], exact dist_le_iff_of_nonempty, end
lemma
bounded_continuous_function.norm_le_of_nonempty
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_lt_iff_of_compact [compact_space α] {f : α →ᵇ β} {M : ℝ} (M0 : 0 < M) : ‖f‖ < M ↔ ∀ x, ‖f x‖ < M
begin simp_rw [norm_def, ←dist_zero_right], exact dist_lt_iff_of_compact M0, end
lemma
bounded_continuous_function.norm_lt_iff_of_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_lt_iff_of_nonempty_compact [nonempty α] [compact_space α] {f : α →ᵇ β} {M : ℝ} : ‖f‖ < M ↔ ∀ x, ‖f x‖ < M
begin simp_rw [norm_def, ←dist_zero_right], exact dist_lt_iff_of_nonempty_compact, end
lemma
bounded_continuous_function.norm_lt_iff_of_nonempty_compact
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "compact_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_const_le (b : β) : ‖const α b‖ ≤ ‖b‖
(norm_le (norm_nonneg b)).2 $ λ x, le_rfl
lemma
bounded_continuous_function.norm_const_le
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "le_rfl" ]
Norm of `const α b` is less than or equal to `‖b‖`. If `α` is nonempty, then it is equal to `‖b‖`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_const_eq [h : nonempty α] (b : β) : ‖const α b‖ = ‖b‖
le_antisymm (norm_const_le b) $ h.elim $ λ x, (const α b).norm_coe_le_norm x
lemma
bounded_continuous_function.norm_const_eq
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_normed_add_comm_group {α : Type u} {β : Type v} [topological_space α] [seminormed_add_comm_group β] (f : α → β) (Hf : continuous f) (C : ℝ) (H : ∀x, ‖f x‖ ≤ C) : α →ᵇ β
⟨⟨λn, f n, Hf⟩, ⟨_, dist_le_two_norm' H⟩⟩
def
bounded_continuous_function.of_normed_add_comm_group
topology.continuous_function
src/topology/continuous_function/bounded.lean
[ "analysis.normed.order.lattice", "analysis.normed_space.operator_norm", "analysis.normed_space.star.basic", "data.real.sqrt", "topology.continuous_function.algebra", "topology.metric_space.equicontinuity" ]
[ "continuous", "seminormed_add_comm_group", "topological_space" ]
Constructing a bounded continuous function from a uniformly bounded continuous function taking values in a normed group.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83