mathlib documentation

topology.​algebra.​open_subgroup

topology.​algebra.​open_subgroup

structure open_add_subgroup (G : Type u_1) [add_group G] [topological_space G] :
Type u_1

The type of open subgroups of a topological additive group.

Reinterpret an open_subgroup as a subgroup.

structure open_subgroup (G : Type u_1) [group G] [topological_space G] :
Type u_1

The type of open subgroups of a topological group.

@[instance]

Equations
@[instance]

Equations
@[simp]
theorem open_add_subgroup.​mem_coe {G : Type u_1} [add_group G] [topological_space G] {U : open_add_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[simp]
theorem open_subgroup.​mem_coe {G : Type u_1} [group G] [topological_space G] {U : open_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[simp]
theorem open_add_subgroup.​mem_coe_opens {G : Type u_1} [add_group G] [topological_space G] {U : open_add_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[simp]
theorem open_subgroup.​mem_coe_opens {G : Type u_1} [group G] [topological_space G] {U : open_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[simp]
theorem open_add_subgroup.​mem_coe_add_subgroup {G : Type u_1} [add_group G] [topological_space G] {U : open_add_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[simp]
theorem open_subgroup.​mem_coe_subgroup {G : Type u_1} [group G] [topological_space G] {U : open_subgroup G} {g : G} :
g ∈ ↑U ↔ g ∈ U

@[ext]
theorem open_subgroup.​ext {G : Type u_1} [group G] [topological_space G] {U V : open_subgroup G} :
(∀ (x : G), x ∈ U ↔ x ∈ V) → U = V

theorem open_add_subgroup.​ext {G : Type u_1} [add_group G] [topological_space G] {U V : open_add_subgroup G} :
(∀ (x : G), x ∈ U ↔ x ∈ V) → U = V

theorem open_subgroup.​ext_iff {G : Type u_1} [group G] [topological_space G] {U V : open_subgroup G} :
U = V ↔ ∀ (x : G), x ∈ U ↔ x ∈ V

theorem open_add_subgroup.​ext_iff {G : Type u_1} [add_group G] [topological_space G] {U V : open_add_subgroup G} :
U = V ↔ ∀ (x : G), x ∈ U ↔ x ∈ V

theorem open_subgroup.​is_open {G : Type u_1} [group G] [topological_space G] (U : open_subgroup G) :

theorem open_subgroup.​one_mem {G : Type u_1} [group G] [topological_space G] (U : open_subgroup G) :
1 ∈ U

theorem open_add_subgroup.​neg_mem {G : Type u_1} [add_group G] [topological_space G] (U : open_add_subgroup G) {g : G} :
g ∈ U → -g ∈ U

theorem open_subgroup.​inv_mem {G : Type u_1} [group G] [topological_space G] (U : open_subgroup G) {g : G} :
g ∈ U → g⁻¹ ∈ U

theorem open_add_subgroup.​add_mem {G : Type u_1} [add_group G] [topological_space G] (U : open_add_subgroup G) {g₁ g₂ : G} :
g₁ ∈ U → g₂ ∈ U → g₁ + g₂ ∈ U

theorem open_subgroup.​mul_mem {G : Type u_1} [group G] [topological_space G] (U : open_subgroup G) {g₁ g₂ : G} :
g₁ ∈ U → g₂ ∈ U → g₁ * g₂ ∈ U

theorem open_subgroup.​mem_nhds_one {G : Type u_1} [group G] [topological_space G] (U : open_subgroup G) :

@[instance]

Equations
def open_subgroup.​prod {G : Type u_1} [group G] [topological_space G] {H : Type u_2} [group H] [topological_space H] :

Equations
@[simp]
theorem open_add_subgroup.​coe_inf {G : Type u_1} [add_group G] [topological_space G] {U V : open_add_subgroup G} :
↑(U ⊓ V) = ↑U ∩ ↑V

@[simp]
theorem open_subgroup.​coe_inf {G : Type u_1} [group G] [topological_space G] {U V : open_subgroup G} :
↑(U ⊓ V) = ↑U ∩ ↑V

@[simp]
theorem open_subgroup.​coe_subset {G : Type u_1} [group G] [topological_space G] {U V : open_subgroup G} :
↑U ⊆ ↑V ↔ U ≤ V

@[simp]
theorem open_add_subgroup.​coe_subset {G : Type u_1} [add_group G] [topological_space G] {U V : open_add_subgroup G} :
↑U ⊆ ↑V ↔ U ≤ V

@[simp]
theorem open_subgroup.​coe_subgroup_le {G : Type u_1} [group G] [topological_space G] {U V : open_subgroup G} :
↑U ≤ ↑V ↔ U ≤ V

theorem subgroup.​is_open_of_mem_nhds {G : Type u_1} [group G] [topological_space G] [has_continuous_mul G] (H : subgroup G) {g : G} :

theorem subgroup.​is_open_mono {G : Type u_1} [group G] [topological_space G] [has_continuous_mul G] {H₁ H₂ : subgroup G} :
H₁ ≤ H₂ → is_open ↑H₁ → is_open ↑H₂

theorem add_subgroup.​is_open_mono {G : Type u_1} [add_group G] [topological_space G] [has_continuous_add G] {H₁ H₂ : add_subgroup G} :
H₁ ≤ H₂ → is_open ↑H₁ → is_open ↑H₂

theorem submodule.​is_open_mono {R : Type u_1} {M : Type u_2} [comm_ring R] [add_comm_group M] [topological_space M] [topological_add_group M] [module R M] {U P : submodule R M} :
U ≤ P → is_open ↑U → is_open ↑P

theorem ideal.​is_open_of_open_subideal {R : Type u_1} [comm_ring R] [topological_space R] [topological_ring R] {U I : ideal R} :
U ≤ I → is_open ↑U → is_open ↑I