Ilias Lazaridis wrote: > > There is a relation, but not an OO 'instance of' one. > > Concretely, in the diagramm V1.3 this means: The answer is really very simple, and much as I loathe to repeat it again (well not really) UML is broken! If it cannot model Ruby correctly then it cannot be "unified". Bug Booch and Rumbaugh about their arrogance. ObNotetoHonorableMrMatsumoto: Not sure if it was a typo but "mataclass" is perfect. -- J Lambert