Starting from known necessary extremality conditions in terms of strict subdifferentials and normals the notion of weak stationarity is introduced. It is defined in terms of initial space elements. The necessary conditions become necessary and sufficient (for stationarity).
Citation
School of Information Technology and Mathematical Sciences, Centre of Information and Applied Optimization, University of Ballarat, POB 663, Ballarat, Vic, 3350. December 2003. Published in Optimization, 53 (2004), 147-164