Henryk Woźniakowski and the complexity of continuous problems

Henryk Woźniakowski is a fascinating colleague and friend. This short paper can only describe a very small part of what Henryk has done. Henryk was born on August 31, 1946, in Lublin, Poland. Lublin is about 150 kilometers south east of Warsaw and today has about 350 000 inhabitants. His family moved to Warsaw in 1950. Henryk studied mathematics and computer science at the University of Warsaw and got his diploma in 1969, Ph.D. in 1972 and habilitation in 1976. From 1972 to 1977, he was assistant professor; in 1977 he became an associate professor in Warsaw. In 1981, Henryk was elected chairman of the Department of Mathematics, Computer Science and Mechanics. He was running as a Solidarity candidate. In the same year, the Senate of the University of Warsaw decided that Henryk should become full professor. However, he had to wait till 1988 that this decision became a reality because of political reasons—Henryk Woźniakowski was for many years one of the leaders of the Solidarnośc movement at the University of Warsaw. In 1989, after political changes in Poland, Henryk