English
For any polynomial p, sumIDeriv p equals the finite sum over i of derivative^i p, i.e., the i-th iterate of derivative summed over i in range.
Русский
Для любого полинома p, sumIDeriv p равен конечной сумме по i от производной в i-й степени, т.е. сумме итераций производной по i.
LaTeX
$$$\forall p:R[X],\ sumIDeriv\ p = \sum_{i\in range\ (p.natDegree+1)} (derivative)^{i} p$$$
Lean4
theorem sumIDeriv_apply (p : R[X]) : sumIDeriv p = ∑ i ∈ range (p.natDegree + 1), derivative^[i] p :=
by
dsimp [sumIDeriv]
exact Finsupp.sum_of_support_subset _ (by simp) _ (by simp)