The Importance of Being Continuous David Jeffrey University of Western Ontario, London, Canada If a function F is the integral of a function f, then F should be continuous on any interval on which f is continuous. There are cases, however, in which CAS return expressions for F which are discontinuous. If students stumble across these cases, then they might get incorrect answers to calculations and be confused. There are two possible ways to avoid this: explain the danger to the students, or change the integration algorithms to guarantee continuous answers. Both possibilities are discussed.