proposition: Lemma cast_intpartn_inj m n eq_m_n : injective (@cast_intpartn m n eq_m_n).
proof: Proof. Proof using. exact: can_inj (cast_intpartnK eq_m_n). Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(div ssralg ssrint ssrnum binomial) tools combclass sorted ordtype