∀ {F : Type u} [inst : Field F] {W : WeierstrassCurve.Projective F} {P : Fin 3 → F},
  P 2 ≠ 0 →
    (MvPolynomial.eval P) W.polynomialY / P 2 ^ 2 = Polynomial.evalEval (P 0 / P 2) (P 1 / P 2) W.toAffine.polynomialY