More about instance overlaps with the GHC library: I need to print in a special way the data of [Equation], (Term, Term), [(Term, Term)], (Equation, Equation). The first can be by defining showList in instance Show Equation. But Show has not a method of showPair. So, I need to write the function showsTermPair and to use it together with another home-made function showsListGeneric. And in ghc-6.4.1, it was sufficient to define the instances and to use only `shows'. About prompt feed-backs from users: this issue of possible fisfeature with overlaps does not look tragic. But with the Map library for Haskell-98, I take it as a considerable loss. It was said that I had a chance to make it standard, if asked about it in time. ----------------- Serge Mechveliani mechvel@botik.ru