proposition: Lemma rpred_nat (S : semiringClosed R) n : n%:R \in S.
proof: Proof. by rewrite rpredMn ?rpred1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)