proposition: Lemma poweRe1 x : 0 <= x -> x `^ 1 = x.
proof: Proof. by move: x => [x'| |]//= x0; rewrite ?powRr1// (negbTE (oner_neq0 _)). 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