unfold nearestℤω
a b c : ℤω
this : OneHom.toFun (↑↑inclusion) 0 = 0
⊢ nearestℤω 0 = 0
a b c : ℤω
this : OneHom.toFun (↑↑inclusion) 0 = 0
⊢ (let y := round (2 * rt3⁻¹ * 0.im);
    { x := round (0.re + 2⁻¹ * ↑y), y := y }) =
    0