proposition: Lemma powRr1 a : 0 <= a -> a `^ 1 = a.
proof: Proof. rewrite le_eqVlt => /predU1P[<-|a0]; first by rewrite powR0// oner_eq0. by rewrite /powR gt_eqF// mul1r lnK// posrE. 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