“…There are several types of definitions for derivatives with fractional order and they include, among others, the variable order derivative (VOD). Such types of models have been discussed in number of research articles [2,3,13,15,16,18,22,35,30,20]. A special attention has been given to the reasonable memory properties that characterize the variable order derivative and that strongly depend on the time or space coordinates [27,37,38,42,4,39,10,8,9].…”