∀ {M : Type u_1} {N : Type u_2} [inst : TopologicalSpace M] [inst_1 : TopologicalSpace N] [inst_2 : Add M]
  [inst_3 : Add N] {L : Type u_3} [inst_4 : Add L] [inst_5 : TopologicalSpace L] (e₁ : M ≃ₜ+ N) (e₂ : N ≃ₜ+ L) (m : M),
  (e₁.trans e₂) m = e₂ (e₁ m)