International Journal of Quantum Chemistry. Vol. 112. 2012. P.. 3076-3090
A survey is given of results related to the inverse function theorem and to necessary and sufficient first- and second-order conditions for extrema in smooth extremal problems with constraints. The main difference between the results here and the classical ones is that the former are valid and meaningful without a priori normality assumptions. © 2012 RAS(DoM) and LMS.