proposition: Lemma nbsurj_small n p: 'Sj(n, (n+p).+1) = 0.
proof: Proof. by rewrite /nbsurj stir_small1 // - addSn leq_addr. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)