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affine_homeomorph (a b : 𝕜) (h : a ≠ 0) : 𝕜 ≃ₜ 𝕜
{ to_fun := λ x, a * x + b, inv_fun := λ y, (y - b) / a, left_inv := λ x, by { simp only [add_sub_cancel], exact mul_div_cancel_left x h, }, right_inv := λ y, by { simp [mul_div_cancel' _ h], }, }
def
affine_homeomorph
topology.algebra
src/topology/algebra/field.lean
[ "topology.algebra.ring.basic", "topology.algebra.group_with_zero", "topology.local_extr", "field_theory.subfield" ]
[ "inv_fun", "mul_div_cancel'", "mul_div_cancel_left" ]
The map `λ x, a * x + b`, as a homeomorphism from `𝕜` (a topological field) to itself, when `a ≠ 0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_local_min.inv {f : α → β} {a : α} (h1 : is_local_min f a) (h2 : ∀ᶠ z in 𝓝 a, 0 < f z) : is_local_max f⁻¹ a
by filter_upwards [h1, h2] with z h3 h4 using (inv_le_inv h4 h2.self_of_nhds).mpr h3
lemma
is_local_min.inv
topology.algebra
src/topology/algebra/field.lean
[ "topology.algebra.ring.basic", "topology.algebra.group_with_zero", "topology.local_extr", "field_theory.subfield" ]
[ "inv_le_inv", "is_local_max", "is_local_min" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.eq_one_or_eq_neg_one_of_sq_eq [ring 𝕜] [no_zero_divisors 𝕜] (hS : is_preconnected S) (hf : continuous_on f S) (hsq : eq_on (f ^ 2) 1 S) : (eq_on f 1 S) ∨ (eq_on f (-1) S)
begin simp_rw [eq_on, pi.one_apply, pi.pow_apply, sq_eq_one_iff] at hsq, -- First deal with crazy case where `S` is empty. by_cases hSe : ∀ (x:α), x ∉ S, { left, intros x hx, exfalso, exact hSe x hx, }, push_neg at hSe, choose y hy using hSe, suffices : ∀ (x:α), x ∈ S → f x = f y, { rcases (hsq hy),...
lemma
is_preconnected.eq_one_or_eq_neg_one_of_sq_eq
topology.algebra
src/topology/algebra/field.lean
[ "topology.algebra.ring.basic", "topology.algebra.group_with_zero", "topology.local_extr", "field_theory.subfield" ]
[ "continuous_on", "discrete_of_t1_of_finite", "is_preconnected", "no_zero_divisors", "pi.one_apply", "pi.pow_apply", "ring", "sq_eq_one_iff" ]
If `f` is a function `α → 𝕜` which is continuous on a preconnected set `S`, and `f ^ 2 = 1` on `S`, then either `f = 1` on `S`, or `f = -1` on `S`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.eq_or_eq_neg_of_sq_eq [field 𝕜] [has_continuous_inv₀ 𝕜] [has_continuous_mul 𝕜] (hS : is_preconnected S) (hf : continuous_on f S) (hg : continuous_on g S) (hsq : eq_on (f ^ 2) (g ^ 2) S) (hg_ne : ∀ {x:α}, x ∈ S → g x ≠ 0) : (eq_on f g S) ∨ (eq_on f (-g) S)
begin rcases hS.eq_one_or_eq_neg_one_of_sq_eq (hf.div hg (λ z hz, hg_ne hz)) (λ x hx, _) with h | h, { refine or.inl (λ x hx, _), rw ←div_eq_one_iff_eq (hg_ne hx), exact h hx }, { refine or.inr (λ x hx, _), specialize h hx, rwa [pi.div_apply, pi.neg_apply, pi.one_apply, div_eq_iff (hg_ne hx), neg_...
lemma
is_preconnected.eq_or_eq_neg_of_sq_eq
topology.algebra
src/topology/algebra/field.lean
[ "topology.algebra.ring.basic", "topology.algebra.group_with_zero", "topology.local_extr", "field_theory.subfield" ]
[ "continuous_on", "div_eq_iff", "div_pow", "div_self", "field", "has_continuous_inv₀", "has_continuous_mul", "is_preconnected", "neg_one_mul", "pi.div_apply", "pi.one_apply", "pow_ne_zero" ]
If `f, g` are functions `α → 𝕜`, both continuous on a preconnected set `S`, with `f ^ 2 = g ^ 2` on `S`, and `g z ≠ 0` all `z ∈ S`, then either `f = g` or `f = -g` on `S`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_preconnected.eq_of_sq_eq [field 𝕜] [has_continuous_inv₀ 𝕜] [has_continuous_mul 𝕜] (hS : is_preconnected S) (hf : continuous_on f S) (hg : continuous_on g S) (hsq : eq_on (f ^ 2) (g ^ 2) S) (hg_ne : ∀ {x:α}, x ∈ S → g x ≠ 0) {y : α} (hy : y ∈ S) (hy' : f y = g y) : eq_on f g S
λ x hx, begin rcases hS.eq_or_eq_neg_of_sq_eq hf hg @hsq @hg_ne with h | h, { exact h hx }, { rw [h hy, eq_comm, ←sub_eq_zero, sub_eq_add_neg, pi.neg_apply, neg_neg, ←mul_two, mul_eq_zero] at hy', cases hy', -- need to handle case of `char 𝕜 = 2` separately { exfalso, exact hg_ne hy hy' }, { rw...
lemma
is_preconnected.eq_of_sq_eq
topology.algebra
src/topology/algebra/field.lean
[ "topology.algebra.ring.basic", "topology.algebra.group_with_zero", "topology.local_extr", "field_theory.subfield" ]
[ "continuous_on", "field", "has_continuous_inv₀", "has_continuous_mul", "is_preconnected", "mul_eq_zero", "mul_zero" ]
If `f, g` are functions `α → 𝕜`, both continuous on a preconnected set `S`, with `f ^ 2 = g ^ 2` on `S`, and `g z ≠ 0` all `z ∈ S`, then as soon as `f = g` holds at one point of `S` it holds for all points.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
group_filter_basis (G : Type u) [group G] extends filter_basis G
(one' : ∀ {U}, U ∈ sets → (1 : G) ∈ U) (mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U) (inv' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x⁻¹) ⁻¹' U) (conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x₀*x*x₀⁻¹) ⁻¹' U)
class
group_filter_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "filter_basis", "group" ]
A `group_filter_basis` on a group is a `filter_basis` satisfying some additional axioms. Example : if `G` is a topological group then the neighbourhoods of the identity are a `group_filter_basis`. Conversely given a `group_filter_basis` one can define a topology compatible with the group structure on `G`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_group_filter_basis (A : Type u) [add_group A] extends filter_basis A
(zero' : ∀ {U}, U ∈ sets → (0 : A) ∈ U) (add' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V + V ⊆ U) (neg' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, -x) ⁻¹' U) (conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x₀+x+-x₀) ⁻¹' U)
class
add_group_filter_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "add_group", "filter_basis" ]
A `add_group_filter_basis` on an additive group is a `filter_basis` satisfying some additional axioms. Example : if `G` is a topological group then the neighbourhoods of the identity are a `add_group_filter_basis`. Conversely given a `add_group_filter_basis` one can define a topology compatible with the group str...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
group_filter_basis_of_comm {G : Type*} [comm_group G] (sets : set (set G)) (nonempty : sets.nonempty) (inter_sets : ∀ (x y), x ∈ sets → y ∈ sets → ∃ z ∈ sets, z ⊆ x ∩ y) (one : ∀ U ∈ sets, (1 : G) ∈ U) (mul : ∀ U ∈ sets, ∃ V ∈ sets, V * V ⊆ U) (inv : ∀ U ∈ sets, ∃ V ∈ sets, ...
{ sets := sets, nonempty := nonempty, inter_sets := inter_sets, one' := one, mul' := mul, inv' := inv, conj' := λ x U U_in, ⟨U, U_in, by simp⟩ }
def
group_filter_basis_of_comm
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "comm_group", "group_filter_basis" ]
`group_filter_basis` constructor in the commutative group case.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one {U : set G} : U ∈ B → (1 : G) ∈ U
group_filter_basis.one'
lemma
group_filter_basis.one
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul {U : set G} : U ∈ B → ∃ V ∈ B, V*V ⊆ U
group_filter_basis.mul'
lemma
group_filter_basis.mul
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv {U : set G} : U ∈ B → ∃ V ∈ B, V ⊆ (λ x, x⁻¹) ⁻¹' U
group_filter_basis.inv'
lemma
group_filter_basis.inv
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
conj : ∀ x₀, ∀ {U}, U ∈ B → ∃ V ∈ B, V ⊆ (λ x, x₀*x*x₀⁻¹) ⁻¹' U
group_filter_basis.conj'
lemma
group_filter_basis.conj
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_subset_self (B : group_filter_basis G) {U : set G} (h : U ∈ B) : U ⊆ U * U
λ x x_in, ⟨1, x, one h, x_in, one_mul x⟩
lemma
group_filter_basis.prod_subset_self
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
N (B : group_filter_basis G) : G → filter G
λ x, map (λ y, x*y) B.to_filter_basis.filter
def
group_filter_basis.N
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "filter", "group_filter_basis" ]
The neighborhood function of a `group_filter_basis`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
N_one (B : group_filter_basis G) : B.N 1 = B.to_filter_basis.filter
by simp only [N, one_mul, map_id']
lemma
group_filter_basis.N_one
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_basis (B : group_filter_basis G) (x : G) : has_basis (B.N x) (λ V : set G, V ∈ B) (λ V, (λ y, x*y) '' V)
has_basis.map (λ y, x * y) to_filter_basis.has_basis
lemma
group_filter_basis.has_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
topology (B : group_filter_basis G) : topological_space G
topological_space.mk_of_nhds B.N
def
group_filter_basis.topology
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "topological_space", "topological_space.mk_of_nhds" ]
The topological space structure coming from a group filter basis.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_eq (B : group_filter_basis G) {x₀ : G} : @nhds G (B.topology) x₀ = B.N x₀
begin rw [topological_space.nhds_mk_of_nhds], { intros x U U_in, rw (B.has_basis x).mem_iff at U_in, rcases U_in with ⟨V, V_in, H⟩, simpa [mem_pure] using H (mem_image_of_mem _ (group_filter_basis.one V_in)), }, { intros x U U_in, rw (B.has_basis x).mem_iff at U_in, rcases U_in with ⟨V, V_in, ...
lemma
group_filter_basis.nhds_eq
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "filter_basis.mem_filter_of_mem", "group_filter_basis", "group_filter_basis.mul", "group_filter_basis.one", "mul_assoc", "nhds", "topological_space.nhds_mk_of_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_one_eq (B : group_filter_basis G) : @nhds G (B.topology) (1 : G) = B.to_filter_basis.filter
by { rw B.nhds_eq, simp only [N, one_mul], exact map_id }
lemma
group_filter_basis.nhds_one_eq
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "map_id", "nhds", "one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_has_basis (B : group_filter_basis G) (x₀ : G) : has_basis (@nhds G B.topology x₀) (λ V : set G, V ∈ B) (λ V, (λ y, x₀ * y) '' V)
by { rw B.nhds_eq, apply B.has_basis }
lemma
group_filter_basis.nhds_has_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_one_has_basis (B : group_filter_basis G) : has_basis (@nhds G B.topology 1) (λ V : set G, V ∈ B) id
by { rw B.nhds_one_eq, exact B.to_filter_basis.has_basis }
lemma
group_filter_basis.nhds_one_has_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_one (B : group_filter_basis G) {U : set G} (hU : U ∈ B) : U ∈ @nhds G B.topology 1
begin rw B.nhds_one_has_basis.mem_iff, exact ⟨U, hU, rfl.subset⟩ end
lemma
group_filter_basis.mem_nhds_one
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "group_filter_basis", "nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_topological_group (B : group_filter_basis G) : @topological_group G B.topology _
begin letI := B.topology, have basis := B.nhds_one_has_basis, have basis' := basis.prod basis, refine topological_group.of_nhds_one _ _ _ _, { rw basis'.tendsto_iff basis, suffices : ∀ U ∈ B, ∃ V W, (V ∈ B ∧ W ∈ B) ∧ ∀ a b, a ∈ V → b ∈ W → a * b ∈ U, by simpa, intros U U_in, rcases mul U_in with ⟨...
instance
group_filter_basis.is_topological_group
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "basis", "basis.prod", "group_filter_basis", "topological_group", "topological_group.of_nhds_one" ]
If a group is endowed with a topological structure coming from a group filter basis then it's a topological group.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_filter_basis (R : Type u) [ring R] extends add_group_filter_basis R
(mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U) (mul_left' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x₀*x) ⁻¹' U) (mul_right' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x*x₀) ⁻¹' U)
class
ring_filter_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "add_group_filter_basis", "ring" ]
A `ring_filter_basis` on a ring is a `filter_basis` satisfying some additional axioms. Example : if `R` is a topological ring then the neighbourhoods of the identity are a `ring_filter_basis`. Conversely given a `ring_filter_basis` on a ring `R`, one can define a topology on `R` which is compatible with the ring ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul {U : set R} (hU : U ∈ B) : ∃ V ∈ B, V * V ⊆ U
mul' hU
lemma
ring_filter_basis.mul
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_left (x₀ : R) {U : set R} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (λ x, x₀*x) ⁻¹' U
mul_left' x₀ hU
lemma
ring_filter_basis.mul_left
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_right (x₀ : R) {U : set R} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (λ x, x*x₀) ⁻¹' U
mul_right' x₀ hU
lemma
ring_filter_basis.mul_right
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
topology : topological_space R
B.to_add_group_filter_basis.topology
def
ring_filter_basis.topology
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "topological_space" ]
The topology associated to a ring filter basis. It has the given basis as a basis of neighborhoods of zero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_topological_ring {R : Type u} [ring R] (B : ring_filter_basis R) : @topological_ring R B.topology _
begin let B' := B.to_add_group_filter_basis, letI := B'.topology, have basis := B'.nhds_zero_has_basis, have basis' := basis.prod basis, haveI := B'.is_topological_add_group, apply topological_ring.of_add_group_of_nhds_zero, { rw basis'.tendsto_iff basis, suffices : ∀ U ∈ B', ∃ V W, (V ∈ B' ∧ W ∈ B') ...
instance
ring_filter_basis.is_topological_ring
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "basis", "basis.prod", "ring", "ring_filter_basis", "topological_ring", "topological_ring.of_add_group_of_nhds_zero" ]
If a ring is endowed with a topological structure coming from a ring filter basis then it's a topological ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
module_filter_basis (R M : Type*) [comm_ring R] [topological_space R] [add_comm_group M] [module R M] extends add_group_filter_basis M
(smul' : ∀ {U}, U ∈ sets → ∃ (V ∈ 𝓝 (0 : R)) (W ∈ sets), V • W ⊆ U) (smul_left' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (λ x, x₀ • x) ⁻¹' U) (smul_right' : ∀ (m₀ : M) {U}, U ∈ sets → ∀ᶠ x in 𝓝 (0 : R), x • m₀ ∈ U)
structure
module_filter_basis
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "add_comm_group", "add_group_filter_basis", "comm_ring", "module", "topological_space" ]
A `module_filter_basis` on a module is a `filter_basis` satisfying some additional axioms. Example : if `M` is a topological module then the neighbourhoods of zero are a `module_filter_basis`. Conversely given a `module_filter_basis` one can define a topology compatible with the module structure on `M`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
group_filter_basis.has_mem : has_mem (set M) (module_filter_basis R M)
⟨λ s B, s ∈ B.sets⟩
instance
module_filter_basis.group_filter_basis.has_mem
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "module_filter_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul {U : set M} (hU : U ∈ B) : ∃ (V ∈ 𝓝 (0 : R)) (W ∈ B), V • W ⊆ U
B.smul' hU
lemma
module_filter_basis.smul
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_left (x₀ : R) {U : set M} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (λ x, x₀ • x) ⁻¹' U
B.smul_left' x₀ hU
lemma
module_filter_basis.smul_left
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_right (m₀ : M) {U : set M} (hU : U ∈ B) : ∀ᶠ x in 𝓝 (0 : R), x • m₀ ∈ U
B.smul_right' m₀ hU
lemma
module_filter_basis.smul_right
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
topology : topological_space M
B.to_add_group_filter_basis.topology
def
module_filter_basis.topology
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "topological_space" ]
The topology associated to a module filter basis on a module over a topological ring. It has the given basis as a basis of neighborhoods of zero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
topology' {R M : Type*} [comm_ring R] {tR : topological_space R} [add_comm_group M] [module R M] (B : module_filter_basis R M) : topological_space M
B.to_add_group_filter_basis.topology
def
module_filter_basis.topology'
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "add_comm_group", "comm_ring", "module", "module_filter_basis", "topological_space" ]
The topology associated to a module filter basis on a module over a topological ring. It has the given basis as a basis of neighborhoods of zero. This version gets the ring topology by unification instead of type class inference.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.has_continuous_smul.of_basis_zero {ι : Type*} [topological_ring R] [topological_space M] [topological_add_group M] {p : ι → Prop} {b : ι → set M} (h : has_basis (𝓝 0) p b) (hsmul : ∀ {i}, p i → ∃ (V ∈ 𝓝 (0 : R)) j (hj : p j), V • (b j) ⊆ b i) (hsmul_left : ∀ (x₀ : R) {i}, p i → ∃ j (hj : p j), (b j) ⊆ (λ...
begin apply has_continuous_smul.of_nhds_zero, { rw h.tendsto_right_iff, intros i hi, rcases hsmul hi with ⟨V, V_in, j, hj, hVj⟩, apply mem_of_superset (prod_mem_prod V_in $ h.mem_of_mem hj), rintros ⟨v, w⟩ ⟨v_in : v ∈ V, w_in : w ∈ (b j)⟩, exact hVj (set.smul_mem_smul v_in w_in) }, { intro m₀,...
lemma
has_continuous_smul.of_basis_zero
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "has_continuous_smul", "has_continuous_smul.of_nhds_zero", "set.smul_mem_smul", "topological_add_group", "topological_ring", "topological_space" ]
A topological add group whith a basis of `𝓝 0` satisfying the axioms of `module_filter_basis` is a topological module. This lemma is mathematically useless because one could obtain such a result by applying `module_filter_basis.has_continuous_smul` and use the fact that group topologies are characterized by their nei...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_smul [topological_ring R] : @has_continuous_smul R M _ _ B.topology
begin let B' := B.to_add_group_filter_basis, letI := B'.topology, haveI := B'.is_topological_add_group, exact has_continuous_smul.of_basis_zero B'.nhds_zero_has_basis (λ _, B.smul) B.smul_left B.smul_right, end
instance
module_filter_basis.has_continuous_smul
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "has_continuous_smul", "has_continuous_smul.of_basis_zero", "topological_ring" ]
If a module is endowed with a topological structure coming from a module filter basis then it's a topological module.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_bases {R M : Type*} [comm_ring R] [add_comm_group M] [module R M] (BR : ring_filter_basis R) (BM : add_group_filter_basis M) (smul : ∀ {U}, U ∈ BM → ∃ (V ∈ BR) (W ∈ BM), V • W ⊆ U) (smul_left : ∀ (x₀ : R) {U}, U ∈ BM → ∃ V ∈ BM, V ⊆ (λ x, x₀ • x) ⁻¹' U) (smul_right : ∀ (m₀ : M) {U}, U ∈ BM → ∃ V ∈ BR, V ⊆ (λ...
{ smul' := begin intros U U_in, rcases smul U_in with ⟨V, V_in, W, W_in, H⟩, exact ⟨V, BR.to_add_group_filter_basis.mem_nhds_zero V_in, W, W_in, H⟩ end, smul_left' := smul_left, smul_right' := begin intros m₀ U U_in, rcases smul_right m₀ U_in with ⟨V, V_in, H⟩, exact mem_of_superset (BR.to...
def
module_filter_basis.of_bases
topology.algebra
src/topology/algebra/filter_basis.lean
[ "order.filter.bases", "topology.algebra.module.basic" ]
[ "add_comm_group", "add_group_filter_basis", "comm_ring", "module", "module_filter_basis", "ring_filter_basis" ]
Build a module filter basis from compatible ring and additive group filter bases.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
uniform_space.completion.coe_zero [has_zero α] : ((0 : α) : completion α) = 0
rfl
lemma
uniform_space.completion.coe_zero
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_neg (a : α) : ((- a : α) : completion α) = - a
(map_coe uniform_continuous_neg a).symm
lemma
uniform_space.completion.coe_neg
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_sub (a b : α) : ((a - b : α) : completion α) = a - b
(map₂_coe_coe a b has_sub.sub uniform_continuous_sub).symm
lemma
uniform_space.completion.coe_sub
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_add (a b : α) : ((a + b : α) : completion α) = a + b
(map₂_coe_coe a b (+) uniform_continuous_add).symm
lemma
uniform_space.completion.coe_add
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_compl : α →+ completion α
{ to_fun := coe, map_add' := coe_add, map_zero' := coe_zero }
def
uniform_space.completion.to_compl
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[]
The map from a group to its completion as a group hom.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_to_compl : continuous (to_compl : α → completion α)
continuous_coe α
lemma
uniform_space.completion.continuous_to_compl
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dense_inducing_to_compl : dense_inducing (to_compl : α → completion α)
dense_inducing_coe
lemma
uniform_space.completion.dense_inducing_to_compl
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "dense_inducing" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.extension [complete_space β] [separated_space β] (f : α →+ β) (hf : continuous f) : completion α →+ β
have hf : uniform_continuous f, from uniform_continuous_add_monoid_hom_of_continuous hf, { to_fun := completion.extension f, map_zero' := by rw [← coe_zero, extension_coe hf, f.map_zero], map_add' := assume a b, completion.induction_on₂ a b (is_closed_eq (continuous_extension.comp continuous_add) ((contin...
def
add_monoid_hom.extension
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "complete_space", "continuous", "continuous_fst", "continuous_snd", "is_closed_eq", "separated_space", "uniform_continuous" ]
Extension to the completion of a continuous group hom.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.extension_coe [complete_space β] [separated_space β] (f : α →+ β) (hf : continuous f) (a : α) : f.extension hf a = f a
extension_coe (uniform_continuous_add_monoid_hom_of_continuous hf) a
lemma
add_monoid_hom.extension_coe
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "complete_space", "continuous", "separated_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.continuous_extension [complete_space β] [separated_space β] (f : α →+ β) (hf : continuous f) : continuous (f.extension hf)
continuous_extension
lemma
add_monoid_hom.continuous_extension
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "complete_space", "continuous", "separated_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.completion (f : α →+ β) (hf : continuous f) : completion α →+ completion β
(to_compl.comp f).extension (continuous_to_compl.comp hf)
def
add_monoid_hom.completion
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "continuous" ]
Completion of a continuous group hom, as a group hom.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.continuous_completion (f : α →+ β) (hf : continuous f) : continuous (f.completion hf : completion α → completion β)
continuous_map
lemma
add_monoid_hom.continuous_completion
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "continuous", "continuous_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.completion_coe (f : α →+ β) (hf : continuous f) (a : α) : f.completion hf a = f a
map_coe (uniform_continuous_add_monoid_hom_of_continuous hf) a
lemma
add_monoid_hom.completion_coe
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.completion_zero : (0 : α →+ β).completion continuous_const = 0
begin ext x, apply completion.induction_on x, { apply is_closed_eq ((0 : α →+ β).continuous_completion continuous_const), simp [continuous_const] }, { intro a, simp [(0 : α →+ β).completion_coe continuous_const, coe_zero] } end
lemma
add_monoid_hom.completion_zero
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "continuous_const", "is_closed_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_monoid_hom.completion_add {γ : Type*} [add_comm_group γ] [uniform_space γ] [uniform_add_group γ] (f g : α →+ γ) (hf : continuous f) (hg : continuous g) : (f + g).completion (hf.add hg) = f.completion hf + g.completion hg
begin have hfg := hf.add hg, ext x, apply completion.induction_on x, { exact is_closed_eq ((f+g).continuous_completion hfg) ((f.continuous_completion hf).add (g.continuous_completion hg)) }, { intro a, simp [(f+g).completion_coe hfg, coe_add, f.completion_coe hf, g.completion_coe hg] } end
lemma
add_monoid_hom.completion_add
topology.algebra
src/topology/algebra/group_completion.lean
[ "topology.algebra.uniform_group", "topology.algebra.uniform_mul_action", "topology.uniform_space.completion" ]
[ "add_comm_group", "continuous", "is_closed_eq", "uniform_add_group", "uniform_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.div_const {x : G₀} (hf : tendsto f l (𝓝 x)) (y : G₀) : tendsto (λa, f a / y) l (𝓝 (x / y))
by simpa only [div_eq_mul_inv] using hf.mul tendsto_const_nhds
lemma
filter.tendsto.div_const
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "div_eq_mul_inv", "tendsto_const_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.div_const {a : α} (hf : continuous_at f a) (y : G₀) : continuous_at (λ x, f x / y) a
by simpa only [div_eq_mul_inv] using hf.mul continuous_at_const
lemma
continuous_at.div_const
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at", "continuous_at_const", "div_eq_mul_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.div_const {a} (hf : continuous_within_at f s a) (y : G₀) : continuous_within_at (λ x, f x / y) s a
hf.div_const _
lemma
continuous_within_at.div_const
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.div_const (hf : continuous_on f s) (y : G₀) : continuous_on (λ x, f x / y) s
by simpa only [div_eq_mul_inv] using hf.mul continuous_on_const
lemma
continuous_on.div_const
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on", "continuous_on_const", "div_eq_mul_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.div_const (hf : continuous f) (y : G₀) : continuous (λ x, f x / y)
by simpa only [div_eq_mul_inv] using hf.mul continuous_const
lemma
continuous.div_const
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous", "continuous_const", "div_eq_mul_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_inv₀ (G₀ : Type*) [has_zero G₀] [has_inv G₀] [topological_space G₀] : Prop
(continuous_at_inv₀ : ∀ ⦃x : G₀⦄, x ≠ 0 → continuous_at has_inv.inv x)
class
has_continuous_inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at", "topological_space" ]
A type with `0` and `has_inv` such that `λ x, x⁻¹` is continuous at all nonzero points. Any normed (semi)field has this property.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_inv₀ {x : G₀} (hx : x ≠ 0) : tendsto has_inv.inv (𝓝 x) (𝓝 x⁻¹)
continuous_at_inv₀ hx
lemma
tendsto_inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on_inv₀ : continuous_on (has_inv.inv : G₀ → G₀) {0}ᶜ
λ x hx, (continuous_at_inv₀ hx).continuous_within_at
lemma
continuous_on_inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on", "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.inv₀ {a : G₀} (hf : tendsto f l (𝓝 a)) (ha : a ≠ 0) : tendsto (λ x, (f x)⁻¹) l (𝓝 a⁻¹)
(tendsto_inv₀ ha).comp hf
lemma
filter.tendsto.inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "tendsto_inv₀" ]
If a function converges to a nonzero value, its inverse converges to the inverse of this value. We use the name `tendsto.inv₀` as `tendsto.inv` is already used in multiplicative topological groups.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.inv₀ (hf : continuous_within_at f s a) (ha : f a ≠ 0) : continuous_within_at (λ x, (f x)⁻¹) s a
hf.inv₀ ha
lemma
continuous_within_at.inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.inv₀ (hf : continuous_at f a) (ha : f a ≠ 0) : continuous_at (λ x, (f x)⁻¹) a
hf.inv₀ ha
lemma
continuous_at.inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.inv₀ (hf : continuous f) (h0 : ∀ x, f x ≠ 0) : continuous (λ x, (f x)⁻¹)
continuous_iff_continuous_at.2 $ λ x, (hf.tendsto x).inv₀ (h0 x)
lemma
continuous.inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.inv₀ (hf : continuous_on f s) (h0 : ∀ x ∈ s, f x ≠ 0) : continuous_on (λ x, (f x)⁻¹) s
λ x hx, (hf x hx).inv₀ (h0 x hx)
lemma
continuous_on.inv₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
units.embedding_coe₀ [group_with_zero G₀] [topological_space G₀] [has_continuous_inv₀ G₀] : embedding (coe : G₀ˣ → G₀)
units.embedding_coe_mk $ continuous_on_inv₀.mono $ λ x, is_unit.ne_zero
theorem
units.embedding_coe₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "embedding", "group_with_zero", "has_continuous_inv₀", "is_unit.ne_zero", "topological_space", "units.embedding_coe_mk" ]
If `G₀` is a group with zero with topology such that `x ↦ x⁻¹` is continuous at all nonzero points. Then the coercion `Mˣ → M` is a topological embedding.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.div {l : filter α} {a b : G₀} (hf : tendsto f l (𝓝 a)) (hg : tendsto g l (𝓝 b)) (hy : b ≠ 0) : tendsto (f / g) l (𝓝 (a / b))
by simpa only [div_eq_mul_inv] using hf.mul (hg.inv₀ hy)
lemma
filter.tendsto.div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "div_eq_mul_inv", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto_mul_iff_of_ne_zero [t1_space G₀] {f g : α → G₀} {l : filter α} {x y : G₀} (hg : tendsto g l (𝓝 y)) (hy : y ≠ 0) : tendsto (λ n, f n * g n) l (𝓝 $ x * y) ↔ tendsto f l (𝓝 x)
begin refine ⟨λ hfg, _, λ hf, hf.mul hg⟩, rw ←mul_div_cancel x hy, refine tendsto.congr' _ (hfg.div hg hy), refine eventually.mp (hg.eventually_ne hy) (eventually_of_forall (λ n hn, mul_div_cancel _ hn)), end
lemma
filter.tendsto_mul_iff_of_ne_zero
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "filter", "mul_div_cancel", "t1_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.div (hf : continuous_within_at f s a) (hg : continuous_within_at g s a) (h₀ : g a ≠ 0) : continuous_within_at (f / g) s a
hf.div hg h₀
lemma
continuous_within_at.div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.div (hf : continuous_on f s) (hg : continuous_on g s) (h₀ : ∀ x ∈ s, g x ≠ 0) : continuous_on (f / g) s
λ x hx, (hf x hx).div (hg x hx) (h₀ x hx)
lemma
continuous_on.div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.div (hf : continuous_at f a) (hg : continuous_at g a) (h₀ : g a ≠ 0) : continuous_at (f / g) a
hf.div hg h₀
lemma
continuous_at.div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at" ]
Continuity at a point of the result of dividing two functions continuous at that point, where the denominator is nonzero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.div (hf : continuous f) (hg : continuous g) (h₀ : ∀ x, g x ≠ 0) : continuous (f / g)
by simpa only [div_eq_mul_inv] using hf.mul (hg.inv₀ h₀)
lemma
continuous.div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous", "div_eq_mul_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on_div : continuous_on (λ p : G₀ × G₀, p.1 / p.2) {p | p.2 ≠ 0}
continuous_on_fst.div continuous_on_snd $ λ _, id
lemma
continuous_on_div
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on", "continuous_on_snd" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.comp_div_cases {f g : α → G₀} (h : α → G₀ → β) (hf : continuous_at f a) (hg : continuous_at g a) (hh : g a ≠ 0 → continuous_at ↿h (a, f a / g a)) (h2h : g a = 0 → tendsto ↿h (𝓝 a ×ᶠ ⊤) (𝓝 (h a 0))) : continuous_at (λ x, h x (f x / g x)) a
begin show continuous_at (↿h ∘ (λ x, (x, f x / g x))) a, by_cases hga : g a = 0, { rw [continuous_at], simp_rw [comp_app, hga, div_zero], exact (h2h hga).comp (continuous_at_id.prod_mk tendsto_top) }, { exact continuous_at.comp (hh hga) (continuous_at_id.prod (hf.div hg hga)) } end
lemma
continuous_at.comp_div_cases
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at", "continuous_at.comp", "div_zero" ]
The function `f x / g x` is discontinuous when `g x = 0`. However, under appropriate conditions, `h x (f x / g x)` is still continuous. The condition is that if `g a = 0` then `h x y` must tend to `h a 0` when `x` tends to `a`, with no information about `y`. This is represented by the `⊤` filter. Note: `filter.tendsto_...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.comp_div_cases {f g : α → G₀} (h : α → G₀ → β) (hf : continuous f) (hg : continuous g) (hh : ∀ a, g a ≠ 0 → continuous_at ↿h (a, f a / g a)) (h2h : ∀ a, g a = 0 → tendsto ↿h (𝓝 a ×ᶠ ⊤) (𝓝 (h a 0))) : continuous (λ x, h x (f x / g x))
continuous_iff_continuous_at.mpr $ λ a, hf.continuous_at.comp_div_cases _ hg.continuous_at (hh a) (h2h a)
lemma
continuous.comp_div_cases
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous", "continuous_at" ]
`h x (f x / g x)` is continuous under certain conditions, even if the denominator is sometimes `0`. See docstring of `continuous_at.comp_div_cases`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_left₀ (c : α) (hc : c ≠ 0) : α ≃ₜ α
{ continuous_to_fun := continuous_mul_left _, continuous_inv_fun := continuous_mul_left _, .. equiv.mul_left₀ c hc }
def
homeomorph.mul_left₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_mul_left", "equiv.mul_left₀" ]
Left multiplication by a nonzero element in a `group_with_zero` with continuous multiplication is a homeomorphism of the underlying type.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_right₀ (c : α) (hc : c ≠ 0) : α ≃ₜ α
{ continuous_to_fun := continuous_mul_right _, continuous_inv_fun := continuous_mul_right _, .. equiv.mul_right₀ c hc }
def
homeomorph.mul_right₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_mul_right", "equiv.mul_right₀" ]
Right multiplication by a nonzero element in a `group_with_zero` with continuous multiplication is a homeomorphism of the underlying type.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_mul_left₀ (c : α) (hc : c ≠ 0) : ⇑(homeomorph.mul_left₀ c hc) = (*) c
rfl
lemma
homeomorph.coe_mul_left₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "homeomorph.mul_left₀" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_left₀_symm_apply (c : α) (hc : c ≠ 0) : ((homeomorph.mul_left₀ c hc).symm : α → α) = (*) c⁻¹
rfl
lemma
homeomorph.mul_left₀_symm_apply
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "homeomorph.mul_left₀" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_mul_right₀ (c : α) (hc : c ≠ 0) : ⇑(homeomorph.mul_right₀ c hc) = λ x, x * c
rfl
lemma
homeomorph.coe_mul_right₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "homeomorph.mul_right₀" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_right₀_symm_apply (c : α) (hc : c ≠ 0) : ((homeomorph.mul_right₀ c hc).symm : α → α) = λ x, x * c⁻¹
rfl
lemma
homeomorph.mul_right₀_symm_apply
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "homeomorph.mul_right₀" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_zpow₀ (x : G₀) (m : ℤ) (h : x ≠ 0 ∨ 0 ≤ m) : continuous_at (λ x, x ^ m) x
begin cases m, { simpa only [zpow_of_nat] using continuous_at_pow x m }, { simp only [zpow_neg_succ_of_nat], have hx : x ≠ 0, from h.resolve_right (int.neg_succ_of_nat_lt_zero m).not_le, exact (continuous_at_pow x (m + 1)).inv₀ (pow_ne_zero _ hx) } end
lemma
continuous_at_zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at", "continuous_at_pow", "pow_ne_zero", "zpow_neg_succ_of_nat", "zpow_of_nat" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on_zpow₀ (m : ℤ) : continuous_on (λ x : G₀, x ^ m) {0}ᶜ
λ x hx, (continuous_at_zpow₀ _ _ (or.inl hx)).continuous_within_at
lemma
continuous_on_zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at_zpow₀", "continuous_on", "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.zpow₀ {f : α → G₀} {l : filter α} {a : G₀} (hf : tendsto f l (𝓝 a)) (m : ℤ) (h : a ≠ 0 ∨ 0 ≤ m) : tendsto (λ x, (f x) ^ m) l (𝓝 (a ^ m))
(continuous_at_zpow₀ _ m h).tendsto.comp hf
lemma
filter.tendsto.zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at_zpow₀", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.zpow₀ (hf : continuous_at f a) (m : ℤ) (h : f a ≠ 0 ∨ 0 ≤ m) : continuous_at (λ x, (f x) ^ m) a
hf.zpow₀ m h
lemma
continuous_at.zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.zpow₀ (hf : continuous_within_at f s a) (m : ℤ) (h : f a ≠ 0 ∨ 0 ≤ m) : continuous_within_at (λ x, f x ^ m) s a
hf.zpow₀ m h
lemma
continuous_within_at.zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.zpow₀ (hf : continuous_on f s) (m : ℤ) (h : ∀ a ∈ s, f a ≠ 0 ∨ 0 ≤ m) : continuous_on (λ x, f x ^ m) s
λ a ha, (hf a ha).zpow₀ m (h a ha)
lemma
continuous_on.zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.zpow₀ (hf : continuous f) (m : ℤ) (h0 : ∀ a, f a ≠ 0 ∨ 0 ≤ m) : continuous (λ x, (f x) ^ m)
continuous_iff_continuous_at.2 $ λ x, (hf.tendsto x).zpow₀ m (h0 x)
lemma
continuous.zpow₀
topology.algebra
src/topology/algebra/group_with_zero.lean
[ "topology.algebra.monoid", "algebra.group.pi", "topology.homeomorph" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
localization.ring_topology : ring_topology (localization M)
ring_topology.coinduced (localization.monoid_of M).to_fun
def
localization.ring_topology
topology.algebra
src/topology/algebra/localization.lean
[ "ring_theory.localization.basic", "topology.algebra.ring.basic" ]
[ "localization", "localization.monoid_of", "ring_topology", "ring_topology.coinduced" ]
The ring topology on `localization M` coinduced from the natural homomorphism sending `x : R` to the equivalence class of `(x, 1)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_one [topological_space M] [has_one M] : continuous (1 : X → M)
@continuous_const _ _ _ _ 1
lemma
continuous_one
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "continuous_const", "topological_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_add (M : Type u) [topological_space M] [has_add M] : Prop
(continuous_add : continuous (λ p : M × M, p.1 + p.2))
class
has_continuous_add
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "topological_space" ]
Basic hypothesis to talk about a topological additive monoid or a topological additive semigroup. A topological additive monoid over `M`, for example, is obtained by requiring both the instances `add_monoid M` and `has_continuous_add M`. Continuity in only the left/right argument can be stated using `has_continuous_co...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_mul (M : Type u) [topological_space M] [has_mul M] : Prop
(continuous_mul : continuous (λ p : M × M, p.1 * p.2))
class
has_continuous_mul
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "continuous_mul", "topological_space" ]
Basic hypothesis to talk about a topological monoid or a topological semigroup. A topological monoid over `M`, for example, is obtained by requiring both the instances `monoid M` and `has_continuous_mul M`. Continuity in only the left/right argument can be stated using `has_continuous_const_smul α α`/`has_continuous_c...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_mul : continuous (λp:M×M, p.1 * p.2)
has_continuous_mul.continuous_mul
lemma
continuous_mul
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_mul.to_has_continuous_smul : has_continuous_smul M M
⟨continuous_mul⟩
instance
has_continuous_mul.to_has_continuous_smul
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "has_continuous_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_continuous_mul.to_has_continuous_smul_op : has_continuous_smul Mᵐᵒᵖ M
⟨show continuous ((λ p : M × M, p.1 * p.2) ∘ prod.swap ∘ prod.map mul_opposite.unop id), from continuous_mul.comp $ continuous_swap.comp $ continuous.prod_map mul_opposite.continuous_unop continuous_id⟩
instance
has_continuous_mul.to_has_continuous_smul_op
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "continuous.prod_map", "has_continuous_smul", "mul_opposite.continuous_unop", "mul_opposite.unop", "prod.swap" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.mul {f g : X → M} (hf : continuous f) (hg : continuous g) : continuous (λx, f x * g x)
continuous_mul.comp (hf.prod_mk hg : _)
lemma
continuous.mul
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_mul_left (a : M) : continuous (λ b:M, a * b)
continuous_const.mul continuous_id
lemma
continuous_mul_left
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "continuous_id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_mul_right (a : M) : continuous (λ b:M, b * a)
continuous_id.mul continuous_const
lemma
continuous_mul_right
topology.algebra
src/topology/algebra/monoid.lean
[ "algebra.big_operators.finprod", "order.filter.pointwise", "topology.algebra.mul_action", "algebra.big_operators.pi", "topology.continuous_function.basic" ]
[ "continuous", "continuous_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83