“…It turns out that some problems, arising in production planning and scheduling, in allocation of resources [2,6,7,14], in decision making [2,7,10,12,14], in the theory of search, in subgradient optimization, in facility location [10,12,13], and so forth, can be described mathematically by using problems like (CSL) and (CSLE), defined by (1.1)-(1.3) and (1.4)-(1.6), respectively. That is why, in order to solve such practical problems, we need some results and methods for solving (CSL) and (CSLE).…”