In tandem, Lipschitz classes serve as a tool for gauging the smoothness and regularity of functions by imposing conditions on the rate at which function values may change.

Five years ago Stander sold his towing company to Super Towing, which was owned by Super Group, which in turn sold it to Craig Lipschitz. After opening and running a similar business in Durban ...

Ms. Resnick’s 1981 portraits of John Belushi were the last taken before he died the following year. Marcia Resnick, via Deborah Bell Photographs, New York and Paul M. Hertzmann, Inc., San Francisco.