proposition: Lemma is_cvg_infs u : cvgn u -> cvgn (infs u).
proof: Proof. by move/is_cvgN/is_cvg_sups; rewrite supsN; move/is_cvgN; rewrite opprK. 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