theorem
MulAction.stabilizer_inf_stabilizer_le_stabilizer_union
{G : Type u_1}
{α : Type u_3}
[Group G]
[MulAction G α]
{s t : Set α}
:
MulAction.stabilizer G s ⊓ MulAction.stabilizer G t ≤ MulAction.stabilizer G (s ∪ t)
theorem
AddAction.stabilizer_inf_stabilizer_le_stabilizer_union
{G : Type u_1}
{α : Type u_3}
[AddGroup G]
[AddAction G α]
{s t : Set α}
:
AddAction.stabilizer G s ⊓ AddAction.stabilizer G t ≤ AddAction.stabilizer G (s ∪ t)
theorem
MulAction.stabilizer_inf_stabilizer_le_stabilizer_inter
{G : Type u_1}
{α : Type u_3}
[Group G]
[MulAction G α]
{s t : Set α}
:
MulAction.stabilizer G s ⊓ MulAction.stabilizer G t ≤ MulAction.stabilizer G (s ∩ t)
theorem
AddAction.stabilizer_inf_stabilizer_le_stabilizer_inter
{G : Type u_1}
{α : Type u_3}
[AddGroup G]
[AddAction G α]
{s t : Set α}
:
AddAction.stabilizer G s ⊓ AddAction.stabilizer G t ≤ AddAction.stabilizer G (s ∩ t)
theorem
MulAction.stabilizer_inf_stabilizer_le_stabilizer_sdiff
{G : Type u_1}
{α : Type u_3}
[Group G]
[MulAction G α]
{s t : Set α}
:
MulAction.stabilizer G s ⊓ MulAction.stabilizer G t ≤ MulAction.stabilizer G (s \ t)
theorem
AddAction.stabilizer_inf_stabilizer_le_stabilizer_sdiff
{G : Type u_1}
{α : Type u_3}
[AddGroup G]
[AddAction G α]
{s t : Set α}
:
AddAction.stabilizer G s ⊓ AddAction.stabilizer G t ≤ AddAction.stabilizer G (s \ t)
theorem
MulAction.stabilizer_union_eq_left
{G : Type u_1}
{α : Type u_3}
[Group G]
[MulAction G α]
{s t : Set α}
(hdisj : Disjoint s t)
(hstab : MulAction.stabilizer G s ≤ MulAction.stabilizer G t)
(hstab_union : MulAction.stabilizer G (s ∪ t) ≤ MulAction.stabilizer G t)
:
MulAction.stabilizer G (s ∪ t) = MulAction.stabilizer G s
theorem
AddAction.stabilizer_union_eq_left
{G : Type u_1}
{α : Type u_3}
[AddGroup G]
[AddAction G α]
{s t : Set α}
(hdisj : Disjoint s t)
(hstab : AddAction.stabilizer G s ≤ AddAction.stabilizer G t)
(hstab_union : AddAction.stabilizer G (s ∪ t) ≤ AddAction.stabilizer G t)
:
AddAction.stabilizer G (s ∪ t) = AddAction.stabilizer G s
theorem
MulAction.stabilizer_union_eq_right
{G : Type u_1}
{α : Type u_3}
[Group G]
[MulAction G α]
{s t : Set α}
(hdisj : Disjoint s t)
(hstab : MulAction.stabilizer G t ≤ MulAction.stabilizer G s)
(hstab_union : MulAction.stabilizer G (s ∪ t) ≤ MulAction.stabilizer G s)
:
MulAction.stabilizer G (s ∪ t) = MulAction.stabilizer G t
theorem
AddAction.stabilizer_union_eq_right
{G : Type u_1}
{α : Type u_3}
[AddGroup G]
[AddAction G α]
{s t : Set α}
(hdisj : Disjoint s t)
(hstab : AddAction.stabilizer G t ≤ AddAction.stabilizer G s)
(hstab_union : AddAction.stabilizer G (s ∪ t) ≤ AddAction.stabilizer G s)
:
AddAction.stabilizer G (s ∪ t) = AddAction.stabilizer G t
theorem
MulAction.op_smul_set_stabilizer_subset
{G : Type u_1}
[Group G]
{a : G}
{s : Set G}
(ha : a ∈ s)
:
MulOpposite.op a • ↑(MulAction.stabilizer G s) ⊆ s
theorem
AddAction.op_vadd_set_stabilizer_subset
{G : Type u_1}
[AddGroup G]
{a : G}
{s : Set G}
(ha : a ∈ s)
:
AddOpposite.op a +ᵥ ↑(AddAction.stabilizer G s) ⊆ s
theorem
MulAction.stabilizer_subset_div_right
{G : Type u_1}
[Group G]
{a : G}
{s : Set G}
(ha : a ∈ s)
:
↑(MulAction.stabilizer G s) ⊆ s / {a}
theorem
AddAction.stabilizer_subset_sub_right
{G : Type u_1}
[AddGroup G]
{a : G}
{s : Set G}
(ha : a ∈ s)
:
↑(AddAction.stabilizer G s) ⊆ s - {a}
theorem
MulAction.stabilizer_finite
{G : Type u_1}
[Group G]
{s : Set G}
(hs₀ : s.Nonempty)
(hs : s.Finite)
:
(↑(MulAction.stabilizer G s)).Finite
theorem
AddAction.stabilizer_finite
{G : Type u_1}
[AddGroup G]
{s : Set G}
(hs₀ : s.Nonempty)
(hs : s.Finite)
:
(↑(AddAction.stabilizer G s)).Finite
theorem
MulAction.smul_set_stabilizer_subset
{G : Type u_1}
[CommGroup G]
{s : Set G}
{a : G}
(ha : a ∈ s)
:
a • ↑(MulAction.stabilizer G s) ⊆ s
theorem
AddAction.vadd_set_stabilizer_subset
{G : Type u_1}
[AddCommGroup G]
{s : Set G}
{a : G}
(ha : a ∈ s)
:
a +ᵥ ↑(AddAction.stabilizer G s) ⊆ s