English
Smeval preserves multiplication: smeval_x(p q) = smeval_x(p) · smeval_x(q).
Русский
Smeval сохраняет умножение: smeval_x(p q) = smeval_x(p) · smeval_x(q).
LaTeX
$$$ (p \cdot q).smeval\ x = p.smeval\ x \cdot q.smeval\ x $$$
Lean4
theorem smeval_mul : (p * q).smeval x = p.smeval x * q.smeval x := by
induction p using Polynomial.induction_on' with
| add r s hr hs => simp only [hr, hs, smeval_add, add_mul]
| monomial n a => simp only [smeval_monomial, smeval_monomial_mul, smul_mul_assoc]