Since the publication of the Design Patterns book, a large number of object-oriented design patterns have been identified and codified. As part of the pattern form, objectoriented design patterns must indicate their relationships with other patterns, but these relationships are typically described very briefly, and different collections of patterns describe different relationships in different ways. In this paper we describe and classify the common relationships between object oriented design patterns. Practitioners can use these relationships to help them identity those patterns which may be applicable to a particular problem, and pattern writers can use these relationships to help them integrate new patterns into the body of the patterns literature. 1.

Abstract. Interaction in a multi-agent system is susceptible to failure. A rigorous development of a multi-agent system must include the specification of fault-tolerance in agent interactions for the agents to be able to continue to function independently. Patterns are presented for the specification in Event-B of fault tolerance in multi-agent interactions. 1