This book provides a systematic in-depth investigation of a class of multiple-context assumption-based multiagent reasoning problems, typical, e.g., for distributed planning, scheduling, and control. First, logical and architectural foundations are provided to construct the two systems XFRMS and MXFRMS allowing the development of more complex utilities. Then the technology developed for XFRMS in the single-agent case is further enhanced to the multiagent situation. The multiagent RMS MXFRMS provides, along with XFRMS, a solid foundation for building more complex utilities, such as plan or schedule maintenance systems. In the final chapter, the software engineer confronted with the task of building a practicable multiagent system can find a discussion of potential uses and future extensions of the systems provided.