∀ (x x_1 : CircleDeg1Liftˣ),
  { toFun := ⇑↑(x * x_1), invFun := ⇑↑(x * x_1)⁻¹, left_inv := ⋯, right_inv := ⋯, map_rel_iff' := ⋯ } =
    { toFun := ⇑↑(x * x_1), invFun := ⇑↑(x * x_1)⁻¹, left_inv := ⋯, right_inv := ⋯, map_rel_iff' := ⋯ }