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CYPRESS is a powerful framework in which to define agents that must accomplish complex goals in dynamic and unpredicatable environments. The application of CYPRESS to the military operations domain attests to the system's usefulness.

The development of CYPRESS involved more than simply engineering the integration of existing systems. The asynchronous replanning facility constitutes one important technological advancement, providing flexible plan execution that can adapt to significant unexpected changes in the world. In addition, interesting technical problems had to be solved in order to bring the system into being. Of greatest significance was the design of the ACT language as a common representation for both executors and planners. In developing ACT, subtle differences between these two classes of systems arose. PRS-CL had to be extended in numerous ways in order to support the execution of plans produced by SIPE-2: the kinds of knowledge employed in automatically generated plans involved constructs not found in the domain procedures defined for previous PRS-CL applications.

Several characteristics distinguish CYPRESS from other systems that provide both planning and reactive execution. Many systems do not use general-purpose planning and so cannot generate plans of sufficient complexity for many application domains of interest. Previous work in run-time replanning has either been limited to synchronous approaches [13][6] or focuses on local, adaptive modifications to rule sets, rather than employing the full look-ahead reasoning of a generative planner [1][8]. The ability to modify a complex, parallel plan at run-time and adapt execution activity to the new plan is, to our knowledge, a new accomplishment.

Aaron Heller
Wed Mar 29 19:31:38 PST 1995