“…Here, f and g are bifunctions from C × C to R satisfying f (x, x) = 0 = g(x, x), for all x ∈ C. In the last few years, bilevel problems have aroused considerable research interests in nonlinear analysis due to its wide variety of applications in different fields ranging from transportation engineering (optimal design, optimal chemical equilibria, and network design, see, e.g., Iiduka 2012;Dempe 2003;Luo et al 1996) to management economics (network facility location, Stackelberg games, principal-agent problem, taxation, optimal pricing, policy decisions, and coordination of multi-divisional firms, see, e.g., Mastroeni 2003;Thuy and Hai 2017;Luo et al 1996;Dempe 2003…”