English
HilbertPoly is homogeneous with respect to scalar multiplication: hilbertPoly(a•p, d) = a•hilbertPoly(p, d).
Русский
Хилбертов полином гомогенный по скалярам: hilbertPoly(a·p, d) = a·hilbertPoly(p, d).
LaTeX
$$$\operatorname{hilbertPoly}(a \cdot p, d) = a \cdot \operatorname{hilbertPoly}(p, d)$$$
Lean4
theorem hilbertPoly_smul (a : F) (p : F[X]) (d : ℕ) : hilbertPoly (a • p) d = a • hilbertPoly p d :=
by
delta hilbertPoly
induction d with
| zero => simp only [smul_zero]
| succ d _ =>
simp only
rw [← sum_def _ fun _ r => r • _, ← sum_def _ fun _ r => r • _, Polynomial.smul_sum,
sum_smul_index' _ _ _ fun i => zero_smul F (preHilbertPoly F d i)]
simp only [smul_assoc]