proposition: Lemma stir_nn n: 'St(n, n) = 1.
proof: Proof. by elim:n=> [//|n Hrec]; rewrite stirS Hrec stir_small1 ? muln0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)