proposition: Lemma expRK : cancel exp ln.
proof: Proof. by move=> x; rewrite /ln; case: xgetP => [x1 _ /eqP/expR_inj //|/(_ x)[]/=]. 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