Types in the modelica language

Modelica is an object-oriented language designed for modeling and simulation of complex physical systems. To enable the possibility for an engineer to discover errors in a model, languages and com-pilers are making use of the concept of types and type checking. This paper gives an overview of the concept of types in the context of the Model-ica language. Furthermore, a new concrete syntax for describing Modelica types is given as a starting point to formalize types in Modelica. Finally, it is concluded that the current state of the Modelica language specification is too informal and should in the long term be augmented by a formal defin-ition