proposition: Lemma mulr0 : right_zero 0%R mulU.
proof: Proof. by move=> x; apply: val_inj; rewrite SubK val0 mulr0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)