proposition: Lemma raddf_eq0 x : injective f -> (f x == 0) = (x == 0).
proof: Proof. by move=> /inj_eq <-; rewrite raddf0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)