∀ {G : Type u_1} {α : Type u_2} [inst : Group G] [inst_1 : MulAction G α] {H : Type u_3} {β : Type u_4}
  [inst_2 : Group H] [inst_3 : MulAction H β] {σ : G → H} {f : α →ₑ[σ] β} {ι : Type u_5} (hf : Function.Injective ⇑f),
  Function.Injective ⇑(Function.Injective.mulActionHom_embedding ι hf)