Hi, I am trying to work out how to use the Algebra.Lattice family of Lattice data structures. Firstly how do I construct a lattice ? What I am wanting to do is to be able to construct a lattice to represent a multiple inheritance hierarchy. Then I to be able to find the Least Upper Bound of a set of classes/types. This is in order to find the type of a multiple case expression. I am not sure if the Haskell classes are actually applicable ? but if they are how do I apply them to the following problem please ? -- Aaron Gray Independent Open Source Software Engineer, Computer Language Researcher, Information Theorist, and amateur computer scientist.