Canonical nderivn_additive n := Additive(nderivn_is_linear n).
Canonical nderivn_linear n := Linear (nderivn_is_linear n).

Lemma nderiv_taylor p x h :
GRing.comm x h -> p.[x + h] = \sum_(i < size p) p^`N(i).[x] * h ^+ i.