∀ {M : Type u_3} {α : Type u_4} {N : Type u_5} {β : Type u_6} [inst : Monoid M] [inst_1 : MulAction M α]
  [inst_2 : Monoid N] [inst_3 : MulAction N β] {φ : M → N} {f : α →ₑ[φ] β},
  Function.Injective ⇑f → ∀ {B : Set β}, MulAction.IsTrivialBlock B → MulAction.IsTrivialBlock (⇑f ⁻¹' B)