Saddle-point optimality criteria involving (ρ, b, d)-invexity and (ρ, b, d)-pseudoinvexity in interval-valued optimisation problems

In this paper, under new generalised convexity assumptions, we investigate some connections between an LU-optimal solution of a variational control problem governed by interval-valued multiple integral functional and a saddle-point associated with an LU-Lagrange functional corresponding to a modified interval-valued variational control problem. Also, in order to illustrate the main results and their effectiveness, we present an application that optimises the mass of a flat plate with interval-valued density that depends on the current point.