El mié, 01-09-2010 a las 16:36 +0600, Alexander.Vladislav.Popov escribió:
It has given me an infinite loop and out-of-memory exception. I tried different variations but not found the valid one and don't know what to do next.
you have to reduce the inner expressions recursively, then pattern-match on those results to simplify: rdc (Add a b) = case (rdc a, rdc b) of (Const 0, x) -> x (x, Const 0) -> x ... You can now be sure that whatever you pattern-match on is already a fully simplified algebraic expression (i.e., a sum of rational powers of x with rational coefficients). This should make it easier to think about the necessary cases you have to handle. Btw., is there a particular reason why you did not try to write the recursion explicitely, but used the function s? Jürgen