At some point a short introduction to the basics of bundle methods is supposed to appear here.
For the moment, however, please consult the literature. For example:
- Jean-Baptiste Hiriart-Urruty and Claude Lemarechal; Convex Analysis and Minimization I, II; Springer, Berlin, 2nd edition 1996. ISBN 3-540-56860-6 (Volume I) and 3-540-56852-2 (Volume II).
- J.F. Bonnans, J. Ch. Gilbert, C. Lemarechal, C. A. Sagastizabal; Numerical Optimization, Theoretical and Practical Aspects; Springer, Berlin 2003. https://doi.org/10.1007/978-3-662-05078-1