As promissed, I am posting my implementation of several modules of numbers in Haskell. Last week was extremely busy, so I managed to test only a part of what I already wrote - the module Fraction. Two other modules: Cofra (complex fraction) and Numerus (generic number) are not thoroughly tested yet -- I will post a similar note soon, after I finish the tests. Two modules "Fraction.hs" and "FractionTest.hs" are currently available at http://www.numeric-quest.com/haskell/index.html along with a short introduction "One view on accuracy and safety of Haskell numbers". Jan