Documentation

Mathlib.GroupTheory.GroupAction.OfQuotient

MulAction of quotient group on fixed points #

Given a MulAction of a group G on A and a normal subgroup H of G, there is a MulAction of the quotient group G ⧸ H on fixedPoints H A.

@[simp]
theorem MulAction.coe_quotient_smul_fixedPoints {G : Type u_1} [Group G] {A : Type u_2} [MulAction G A] {H : Subgroup G} [H.Normal] (g : G) (a : (fixedPoints (↥H) A)) :
g a = g a
@[simp]
theorem MulAction.quotient_out_smul_fixedPoints {G : Type u_1} [Group G] {A : Type u_2} [MulAction G A] {H : Subgroup G} [H.Normal] (g : G H) (a : (fixedPoints (↥H) A)) :