proposition: Fact le_Young_anti : antisymmetric le_Young.
proof: Proof. rewrite /le_Young => [][p Hp] [q Hq] /= /andP[inclpq inclqp]. by apply val_inj => /=; apply: included_anti. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(div ssralg ssrint ssrnum binomial) tools combclass sorted ordtype