proposition: Fact null_fun_is_semi_additive : semi_additive (\0 : U -> V).
proof: Proof. by split=> // x y /=; rewrite addr0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)