to see schatchen in action, try tracing m2 and m1, and then call integrate on, for example, integrate(1/(a*x^2+b),x) It is in the file schatc.lisp and appears to have been modified from Moses' code by RZ (Richard Zippel) at some time in the past. It is, I believe, also used for simplifying SUMs heuristically. RJF