Foundations of Meta-Pyramids: Languages vs. Metamodels

Despite the recent interest for Model Driven Engineering ap- proaches, the so-called four-layers metamodelling architecture is subject to a lot of debate. The relationship that exists between a model and a metamodel is often called instanceOf, but this terminology, which comes directly from the object oriented technology, is not appropriate for the modelling of similar meta-pyramids in other domains. The goal of this paper is to study which are the foundations of the meta-pyramids independently from a particular tech- nology. This paper is actually the second episode of the series "From Ancient Egypt to Model Driven Engineering". In the pilot episode, the notion of me- gamodel was introduced to model essential Model Driven Engineering con- cepts. The notion of models was thoroughly discussed and only one associa- tion, namely RepresentationOf was introduced. In this paper the megamodel is extended with one fundamental relation in order to model the notion of lan- guages and of metamodels. It is shown how Thotus the Baboon helped Nivizeb the priest in designing strong foundations for meta-pyramids. The secrets of some ancient pyramids are revealed.