On a Graph-Based Semantics for UML Class and Object Diagrams

In this paper we propose a formal extension of type graphs with notions that are commonplace in the UML and have long proven their worth in that context: namely, inheritance, multiplicity, containment and the like. We believe the absence of a comprehensive and commonly agreed upon formalisation of these notions to be an important and, unfortunately, often ignored omission. Since our eventual aim (shared by many researchers) is to give unambiguous, formal semantics to the UML using the theory of graphs and graph transformation, in this paper we propose a set of definitions to repair this omission. With respect to previous work in this direction, our aim is to arrive at more comprehensive and at the same time simpler definitions.\u

GMF: A Model Migration Case for the Transformation Tool Contest

Using a real-life evolution taken from the Graphical Modeling Framework, we invite submissions to explore ways in which model transformation and migration tools can be used to migrate models in response to metamodel adaptation.Comment: In Proceedings TTC 2011, arXiv:1111.440

Formality: The Object Constraint Language and its Application in the UML Metamodel

Within the field of object technology it is becoming recognised that constraints are a good way to produce more precise and formal specifications than with diagrams alone. Evidence of this is that UML incorporates a standard constraint language called OCL (Object Constraint Language). The availability of OCL will encourage UML users to add constraints to their UML models. This paper explains OCL and demonstrates its applicability. Probably the largest application of OCL to date was its use to define the metamodel of UML, and the experiences gained in this application are discussed

Defining the Context of OCL Expressions

Expressions written in Object Constraint Language (OCL) within a UML model assume a context, depending upon where they are written. Currently the exact nature of this context is not fully defined. Furthermore there is no mechanism for defining the context for OCL expressions in extensions to UML. This paper defines the context of OCL expressions, and proposes precise and flexible mechanisms for how to specify this context

Defining UML Family Members using Prefaces

The Unified Modeling Language is extensible, and so can be regarded as a family of languages. Implicitly or explicitly, any particular UML model should be accompanied by a definition of the particular UML family member used for the model. The definition should cover syntactic and semantic issues. This paper proposes a mechanism for associating models with such definitions. Any particular definition would form what we call a preface. The name is intended to suggest that the definition of a particular UML family member must conceptually come before any model built using that family member. A preface would be large, and should be organised using packages. This would allow large amounts of sharing between different prefaces. The paper proposes that prefaces should have an axiomatic style of semantics, through not necessarily fully formal, and it offers a general approach to semantics that would reduce problems of inconsistency within a large preface, based on the idea of general cases and special case