“…Our main result is the following improvement of Theorem 1.1. that is, Theorem 14 from (Chandok et al, 2016 (Kadelburg et al, 2016), , (Radenović, 2015a), (Radenović, 2016), (Radenović, 2015b Proof. Putting in Theorem 2.1. for all we obtain the result.…”