Shenawy, , S2019-11-232019-11-232011Cited References in Web of Science Core Collection: 181224-2780https://cutt.ly/peVecT6Accession Number: WOS:000289683600014Let A be an open connected subset of a C(infinity) complete simply connected 2-dimensional Riemannian manifold without conjugate points W(2). The main result of this short article states that: a point x of A has a local maximal visibility if and only if x is a point of the convex kernel of A. Thus we obtain a Tietze-type theorem in W(2).enmaximal visibilitystarshaped setTietze-type theoremconjugate pointskernelArticle