∀ {G : Type u_6} {inst : Group G} {toFun : G → ℝ} {map_one' : toFun 1 = 0}
  {mul_le' : ∀ (x y : G), toFun (x * y) ≤ toFun x + toFun y} {inv' : ∀ (x : G), toFun x⁻¹ = toFun x} {toFun_1 : G → ℝ}
  {map_one'_1 : toFun_1 1 = 0} {mul_le'_1 : ∀ (x y : G), toFun_1 (x * y) ≤ toFun_1 x + toFun_1 y}
  {inv'_1 : ∀ (x : G), toFun_1 x⁻¹ = toFun_1 x},
  { toFun := toFun, map_one' := map_one', mul_le' := mul_le', inv' := inv' } =
      { toFun := toFun_1, map_one' := map_one'_1, mul_le' := mul_le'_1, inv' := inv'_1 } →
    toFun = toFun_1