∀ {α : Sort u_1} {β : Sort u_3} {γ : Sort u_2} {δ : Sort u_4} (h : α ≃ β) (h' : γ ≃ δ) (x : α ↪ γ),
  (fun f => Function.Embedding.congr h.symm h'.symm f) ((fun f => Function.Embedding.congr h h' f) x) = x