Dynamic type Information in Process Types

Static checking of process types ensures that each object accepts all messages received from concurrent clients, although the set of acceptable messages can depend on the object's state. However, conventional approaches of using dynamic type information (e.g., checked type casts) are not applicable in the current process type model, and the typing of self-references is too restrictive. In this paper a reenement of the model is proposed. It solves these problems so that it is easy to handle, for example, heterogeneous collections.