“…The response of the researchers resulted in various types of metrics, such as the cone metric, the partially ordered metric, the modular metric, and more recently the complex-valued metrics proposed by Huang and Zhang [6], Matthew [7], Azam et al [8], and Murthy et al [9]. For more details on the topic, see [10][11][12][13][14][15][16]) and the references therein.…”