proposition: Lemma subEprod x y : x `\` y = (x.1 `\` y.1, x.2 `\` y.2).
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)