Gap functions for a system of generalized vector quasi-equilibrium problems with set-valued mappings

Throughout this paper, let Z, E, and F be topological vector spaces, let X ⊆ E and Y ⊆ F be nonempty, closed, and convex subsets. Let D : X → 2X , T : X → 2Y and Ψ : X ×Y × X → 2Z be set-valued mappings, and let C : X → 2Z be a set-valued mapping such that C(x) is a closed pointed and convex cone with intC(x) = ∅ for each x ∈ X , where intC(x) denotes the interior of the set C(x). Then the generalized vector quasi-equilibrium problem with set-valued mappings (GVQEP) is to find (x, y) in X ×Y such that