∀ {σ : Type u_1} (m m_1 : MonomialOrder σ) (e_m : m = m_1) {R : Type u_2} [inst : CommRing R] {b b_1 : MvPolynomial σ R}
  (e_b : b = b_1) (hb : IsUnit (m.leadingCoeff b)) (f f_1 : MvPolynomial σ R),
  f = f_1 → m.reduce hb f = m_1.reduce ⋯ f_1