On Mon, 28 May 2001, Mathieu Bouchard wrote: > Three months ago I have written: > > module ArithInterface > def +(other); raise NotImplementedError; end > def -@; raise NotImplementedError; end > end > > module ArithMixin > include ArithInterface > def -(other) > self + - other > end > end > > and then I stopped there. ;-) > Well, its a start... ;-) /Robert