proposition: Lemma H4draw_win_le i : f1 i <= draw -> f2 edraw ewin i <= edraw.
proof: Proof. case: f1 (@H4draw_win_loss i) (@H4draw_win_draw i) => //. by move=> /(_ (refl_equal _)) /leq_trans->. by move=> _ /(_ (refl_equal _)) /andP[]. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(all_algebra)