proposition: Fact amull_is_linear : linear amull.
proof: Proof. move=> a u v; apply/lfunP => w. by rewrite !lfunE /= scale_lfunE !lfunE /= mulrDl scalerAl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)