OclType - A Type or Metatype ?

While the type system proposed in the OCL Standard Library of the latest OCL 2.0 proposal seems to be considerably stable by now, there are still some deficiencies in the definition of operations for type casts and type conformance checks. This results from the fact that the types defined on the user-level are currently not well represented in the OCL Standard Library. This article presents a new modeling approach to adequately capture these types in the OCL Standard Library through the UML core concept called powertype. The powertype concept allows to model a metaelement on the architectural user level M1. By this approach, we propose an enhanced structure of the OCL Standard Library that prescribes a controlled way for accessing the metalevel.