Herbert Fritsch wrote: >>>> b / (2.0 + a) > 0.80000000000000004 > > There must be something wrong. I' running the new Suse 9.0. No :-) That's the way *all* floating point operations work, nothing python-specific here. See http://www.python.org/doc/faq/general.html#why-are-floating-point-calculations-so-inaccurate Peter