1 Retraction to: Bulletin of the Iranian Mathematical Society (2019) 45:1821–1829 https://doi.org/10.1007/s41980-019-00232-4

The Editor-in-Chief has retracted the original article [1] because it significantly overlaps with a number of previously published articles [2,3,4]. This article is therefore redundant.

All authors do not agree to this retraction.