Subgroups of cyclic groups #
Develop properties of finite cyclic groups and subgroups of cyclic groups.
Main statements #
isCyclic_of_prime_cardproves that a finite group of prime order is cyclic.Subgroup.isCyclicproves that subgroups of cyclic groups are cyclic.
Tags #
cyclic group
theorem IsCyclic.exists_generator {α : Type u_1} [Group α] [IsCyclic α] :
∃ (g : α), ∀ (x : α), x ∈ Subgroup.zpowers g
theorem IsAddCyclic.exists_generator {α : Type u_1} [AddGroup α] [IsAddCyclic α] :
∃ (g : α), ∀ (x : α), x ∈ AddSubgroup.zmultiples g
theorem AddSubgroup.isAddCyclic_iff_exists_zmultiples_eq_top {α : Type u_1} [AddGroup α] (H : AddSubgroup α) :
instance AddSubgroup.isAddCyclic_zmultiples {G : Type u_2} [AddGroup G] (g : G) :
IsAddCyclic ↥(zmultiples g)
theorem isAddCyclic_of_addOrderOf_eq_card {α : Type u_1} [AddGroup α] [Finite α] (x : α) (hx : addOrderOf x = Nat.card α) :
theorem isAddCyclic_of_card_le_addOrderOf {α : Type u_1} [AddGroup α] [Finite α] (x : α) (hx : Nat.card α ≤ addOrderOf x) :
theorem orderOf_eq_card_of_forall_mem_zpowers {α : Type u_1} [Group α] {g : α} (hx : ∀ (x : α), x ∈ Subgroup.zpowers g) :
theorem addOrderOf_eq_card_of_forall_mem_zmultiples {α : Type u_1} [AddGroup α] {g : α} (hx : ∀ (x : α), x ∈ AddSubgroup.zmultiples g) :
theorem orderOf_eq_card_of_forall_mem_powers {α : Type u_1} [Group α] {g : α} (hx : ∀ (x : α), x ∈ Submonoid.powers g) :
theorem addOrderOf_eq_card_of_forall_mem_multiples {α : Type u_1} [AddGroup α] {g : α} (hx : ∀ (x : α), x ∈ AddSubmonoid.multiples g) :
theorem orderOf_eq_card_of_zpowers_eq_top {G : Type u_2} [Group G] {g : G} (h : Subgroup.zpowers g = ⊤) :
theorem addOrderOf_eq_card_of_zmultiples_eq_top {G : Type u_2} [AddGroup G] {g : G} (h : AddSubgroup.zmultiples g = ⊤) :
theorem Infinite.orderOf_eq_zero_of_forall_mem_zpowers {α : Type u_1} [Group α] [Infinite α] {g : α} (h : ∀ (x : α), x ∈ Subgroup.zpowers g) :
theorem Infinite.addOrderOf_eq_zero_of_forall_mem_zmultiples {α : Type u_1} [AddGroup α] [Infinite α] {g : α} (h : ∀ (x : α), x ∈ AddSubgroup.zmultiples g) :
instance AddSubgroup.isAddCyclic {α : Type u_1} [AddGroup α] [IsAddCyclic α] (H : AddSubgroup α) :
IsAddCyclic ↥H
theorem isCyclic_of_injective {G : Type u_2} {G' : Type u_3} [Group G] [Group G'] [IsCyclic G'] (f : G →* G') (hf : Function.Injective ⇑f) :
IsCyclic G
theorem isAddCyclic_of_injective {G : Type u_2} {G' : Type u_3} [AddGroup G] [AddGroup G'] [IsAddCyclic G'] (f : G →+ G') (hf : Function.Injective ⇑f) :
theorem AddSubgroup.isAddCyclic_of_le {G : Type u_2} [AddGroup G] {H H' : AddSubgroup G} (h : H ≤ H') [IsAddCyclic ↥H'] :
IsAddCyclic ↥H
theorem IsAddCyclic.card_nsmul_eq_zero_le {α : Type u_1} [AddGroup α] [DecidableEq α] [Fintype α] [IsAddCyclic α] {n : ℕ} (hn0 : 0 < n) :
theorem IsCyclic.exists_monoid_generator {α : Type u_1} [Group α] [Finite α] [IsCyclic α] :
∃ (x : α), ∀ (y : α), y ∈ Submonoid.powers x
theorem IsAddCyclic.exists_addMonoid_generator {α : Type u_1} [AddGroup α] [Finite α] [IsAddCyclic α] :
∃ (x : α), ∀ (y : α), y ∈ AddSubmonoid.multiples x
theorem IsAddCyclic.exists_ofOrder_eq_natCard {α : Type u_1} [AddGroup α] [h : IsAddCyclic α] :
∃ (g : α), addOrderOf g = Nat.card α
noncomputable def MulDistribMulAction.toMonoidHomZModOfIsCyclic (G : Type u_2) [Group G] (M : Type u_4) [Monoid M] [IsCyclic G] [MulDistribMulAction M G] {n : ℕ} (hn : Nat.card G = n) :
A distributive action of a monoid on a finite cyclic group of order n factors through an
action on ZMod n.
Equations
- MulDistribMulAction.toMonoidHomZModOfIsCyclic G M hn = { toFun := fun (m : M) => ↑⋯.choose, map_one' := ⋯, map_mul' := ⋯ }
Instances For
theorem IsCyclic.unique_zpow_zmod {α : Type u_1} {a : α} [Group α] [Fintype α] (ha : ∀ (x : α), x ∈ Subgroup.zpowers a) (x : α) :
theorem IsAddCyclic.unique_zsmul_zmod {α : Type u_1} {a : α} [AddGroup α] [Fintype α] (ha : ∀ (x : α), x ∈ AddSubgroup.zmultiples a) (x : α) :
theorem IsCyclic.image_range_orderOf {α : Type u_1} {a : α} [Group α] [Fintype α] [DecidableEq α] (ha : ∀ (x : α), x ∈ Subgroup.zpowers a) :
theorem IsAddCyclic.image_range_addOrderOf {α : Type u_1} {a : α} [AddGroup α] [Fintype α] [DecidableEq α] (ha : ∀ (x : α), x ∈ AddSubgroup.zmultiples a) :
theorem IsCyclic.image_range_card {α : Type u_1} {a : α} [Group α] [Fintype α] [DecidableEq α] (ha : ∀ (x : α), x ∈ Subgroup.zpowers a) :
theorem IsAddCyclic.image_range_card {α : Type u_1} {a : α} [AddGroup α] [Fintype α] [DecidableEq α] (ha : ∀ (x : α), x ∈ AddSubgroup.zmultiples a) :