Simon, Here's a minor quibble with the organization of the Report and Library, not with the content. Sorry if this has been brought up before. In section 4.3.3, Derived Instances, of the Report there is The only classes in the Prelude for which derived instances are allowed are Eq, Ord, Enum, Bounded, Show, and Read, all mentioned in Figure 5, ... Classes defined by the standard libraries may also be derivable. In the introduction to the Library Report there is Classes defined in libraries may be derivable. This report includes the derivation of such classes when appropriate. Now, unless I missed something, the only class in the Library Report which is derivable is Ix. I would argue for bringing the Ix class into the Report for these reasons * One does not have to search through the Library Report to determine what is derivable. * I think one would expect that the Libraries contain stuff that could be implemented in Haskell by the user. Until Haskell has the ability to allow for user-defined derivable classes, Ix cannot be defined by the user. - Mark