The ideas behind this paper were generated as a result of the problems encountered by an HND Engineering student at Trent Polytechnic. The student was studying on the second year of a Production Engineering course, a course which contains only very little formal mathematics. He had been given by a member of the Production Engineering staff a mini‐project on a real computer‐controlled drilling machine, and unfortunately the engineer who had given the project did not appreciate the problems the student would have. The project required the writing and verifying of a program which would move the drilling‐bit along a two dimensional curve which was defined by a few points only.