English
For any ring R and r ∈ R, the image of the constant polynomial C r under derivativeFinsupp is the finitely supported function with a single nonzero entry at 0 equal to C r.
Русский
Для любого кольца R и r ∈ R образ константного полинома C r под derivativeFinsupp равен конечной опоре с единственным ненулевым элементом в позиции 0 равным C r.
LaTeX
$$$$ \mathrm{derivativeFinsupp}(\,C(r)\,)=\mathrm{single}(0, C(r)) $$$$
Lean4
@[simp]
theorem derivativeFinsupp_C (r : R) : derivativeFinsupp (C r : R[X]) = .single 0 (C r) :=
by
ext i : 1
match i with
| 0 => simp
| i + 1 => simp