proposition: Lemma expeR_gt0 x : -oo < x -> 0 < expeR x.
proof: Proof. by case: x => //= r; rewrite lte_fin expR_gt0. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(boolp classical_sets functions) mathcomp(mathcomp_extra) reals ereal signed topology normedtype landau sequences derive realfun itv convex