Symmetric duality for a class of nonlinear fractional programming problems ✩

A pair of symmetric dual nonlinear fractional programming problems is presented and duality theorems are established under pseudoinvexity–pseudoincavity (and invexity– incavity, respectively) type assumptions on the kernel function. Special cases are particularly discussed to show that this paper extends some work appeared in this area.  2002 Elsevier Science (USA). All rights reserved.