proposition: Fact ffun_scale1 : left_id 1 ffun_scale.
proof: Proof. by move=> f; apply/ffunP=> a; rewrite !ffunE scale1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)