An existence result for quasiequilibrium problems in separable Banach spaces

We establish the existence of solutions for a quasiequilibrium problem in the context of infinite-dimensional separable Banach spaces. To this purpose, we use a fixed point technique which is based on the notion of inside point of a convex set that appeared in 1956 in a paper by E. Michael [12]. As particular case, we provide the existence of a generalized Nash equilibrium requiring the lower semicontinuity of the strategy map and the closedness of the fixed point set.