Sufficiency and Duality for Nonsmooth Interval-Valued Optimization Problems via Generalized Invex-Infine Functions

In this paper, a new concept of generalized-affineness type of functions is introduced. This class of functions is more general than some of the corresponding ones discussed in Chuong (Nonlinear Anal Theory Methods Appl 75:5044–5052, 2018), Sach et al. (J Global Optim 27:51–81, 2003) and Nobakhtian (Comput Math Appl 51:1385–1394, 2006). These concepts are used to discuss the sufficient optimality conditions for the interval-valued programming problem in terms of the limiting/Mordukhovich subdifferential of locally Lipschitz functions. Furthermore, two types of dual problems, namely Mond–Weir type and mixed type duals are formulated for an interval-valued programming problem and usual duality theorems are derived. Our results improve and generalize the results appeared in Kummari and Ahmad (UPB Sci Bull Ser A 82(1):45–54, 2020).