proposition: Lemma cvgNy_esups u : u @ \oo --> -oo -> esups u @ \oo --> -oo.
proof: Proof. move=> /cvgNy_limn_einf_sup[_ uoo]; apply/cvg_closeP. by split; [exact: is_cvg_esups|rewrite closeE// -limn_esup_lim]. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(set_interval) reals ereal signed topology normedtype landau