The concept of "variations" has undergone significant development in relation to applications in optimization, equilibrium, and control since its beginnings in the minimization of integral functionals.
It also relates to types of perturbation and approximation that are best described by "set convergence," variational convergence of functions, and other phenomena. It does not simply refer to limited movement away from a point.
Beyond classical and convex analysis, this book creates a coherent framework and offers a thorough explanation of variational geometry and subdifferential calculus in finite dimensions. Additionally discussed are duality, maximal monotone mappings, second-order subderivatives, measurable selections, and normal integrands.
The alterations in this third printing mostly relate to reference omissions and other typographical adjustments that were discovered in earlier printings. Many of these were brought to the authors' attention during subsequent readings by them, their students, and several colleagues noted in the Preface.
Additionally, the writers enhanced a few statements with slightly weaker assumptions or, in a few cases, strengthened the conclusions. They also included a few illustrative examples.