proposition: Lemma euler_nn n: 'Eu(n.+1,n) = 1.
proof: Proof. elim :n => [// | n Hrec]; rewrite eulerS Hrec euler_small1 ?subSnn // muln0//. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)