In this paper we extend a (scalarized) generalized type-I invexity into a v
ector invexity (V-type I). A number of sufficiency results are established
using Lagrange multiplier conditions and under various types of generalized
V-type I requirements. Weak, strong, and converse duality theorems are pro
ved in the generalized V-invexity type I setting. (C) 2001 Academic Press.