Hi all, I'm currently embarking on my first major project in Haskell, after dabbling with it for several years, and seem to keep finding myself in situations where I create a typeclass that seems to be some sort of specialisation of another, more general typeclass. Given that this is the case, I've then decided that all instances of the specific class should therefore also be instances of the general class, and arrived at the following method of doing so, using the FlexibleInstances and UndecidableInstances extensions to GHC: {-# LANGUAGE FlexibleInstances, UndecidableInstances #-} class Max a where maximum :: a -> a -> a instance (Ord a) => Max a where maximum = max (Obviously, this is a very trivial, and rather silly example - I'm not really trying to implement a class called 'Max'). However, I'd be curious to know if (a) There are better or more idiomatic ways of achieving the same effect, and (b) Whether or not I should be doing this at all; It did occur to me that this seems rather trying to re-implement OOP-style inheritance with typeclasses, and therefore perhaps not a very Haskellish approach to designing software. Therefore - are there better ways to achieve this, or should I not be doing this at all, and, if the latter, what would be the best means of achieving a similar result (i.e. a typeclass that implements all the functionality of one or more others, optionally with some additional specialism)? Many thanks, Tim