English
Reflect sends constant times X^n to the constant times X^{revAt N n}.
Русский
Reflect отправляет константу, умноженную на X^n, в константу, умноженную на X^{revAt N n}.
LaTeX
$$$\\mathrm{reflect}\\ N\\ (C\\ c\\cdot X^n) = C\\ c\\cdot X^{\\mathrm{revAt}\\ N\\ n}.$$$
Lean4
theorem reflect_C_mul_X_pow (N n : ℕ) {c : R} : reflect N (C c * X ^ n) = C c * X ^ revAt N n :=
by
ext
rw [reflect_C_mul, coeff_C_mul, coeff_C_mul, coeff_X_pow, coeff_reflect]
split_ifs with h
· rw [h, revAt_invol, coeff_X_pow_self]
· rw [notMem_support_iff.mp]
intro a
rw [← one_mul (X ^ n), ← C_1] at a
apply h
rw [← mem_support_C_mul_X_pow a, revAt_invol]