proposition: Lemma ereal_inf_lb S : lbound S (ereal_inf S).
proof: Proof. by move=> x Sx; rewrite /ereal_inf leeNl; apply ereal_sup_ub; exists x. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(fsbigop cardinality set_interval) reals signed topology constructive_ereal