proposition: Lemma ereal_inf1 x : ereal_inf [set x] = x.
proof: Proof. by rewrite /ereal_inf image_set1 ereal_sup1 oppeK. 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