Although Shitov’s paper [2] was cited in [1], the credit given to Shitov for the use of his idea in Lemma 2.8 and consequently Corollary 2.16 was not sufficient. The author would like to give full credit to Yaroslav Shirov [2] for his idea implemented in Lemma 2.8 and Corollary 2.16 of [1].