proposition: Lemma stir_small1 n p: n < p -> 'St(n,p) = 0.
proof: Proof. by move /subnKC => <-; rewrite addSn stir_small. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)