I did my undergraduate studies at the faculty of Electrical Engineering of Delft University of Technology in The Netherlands from 1984 to 1988. My main interests were computer engineering, artificial intelligence and logic programming. In 1987 I spent three months at Philips Natlab in Eindhoven during which I wrote a small operating system for an image recognition system. This practical work was supervised by dr. L.J. de Haas. I did my Masters thesis work in the Theoretical Computing Science group. For this thesis work I developed a partial evaluation program for Prolog. The exam committee consisted of prof.dr. S.C. van Westrhenen, prof.dr.ir. A.J. van de Goor and ir. R. Sommerhalder (thesis supervisor).