In this paper, we study optimality conditions of quasi approximate solutions
for nonsmooth semi-infinite programming problems (for short, (SIP)), in
terms of ?-upper semi-regular semi-convexificator which is introduced here.
Some classes of functions, namely (?-?*?)-pseudoconvex functions and (?-?*?)-quasiconvex functions with respect to a given ?-upper semi-regular
semi-convexificator are introduced, respectively. By utilizing these new
concepts, sufficient optimality conditions of approximate solutions for the
nonsmooth (SIP) are established. Moreover, as an application, optimality
conditions of quasi approximate weakly efficient solution for nonsmooth
multi-objective semi-infinite programming problems (for short, (MOSIP)) are
presented.