Traditionally, generative planning and plan execution have been considered distinct activities. This dichotomy has lead to the development of generative planning systems that ignore execution issues and reactive plan execution systems that cannot synthesize new plans at run-time. Not surprisingly, different representations have developed for defining operators for synthesizing and executing plans, making it difficult to support tightly integrated plan generation and plan execution systems.
The online postcript document The Act Formalism provides a brief overview of the Act formalism, including a BNF grammar specification of Act. Additional details on the semantics and backgound on Act can be found in the references provided below.
The Act-Editor is a graphical browsing and editing system for procedural knowledge expressed as Acts. Through it, Acts can be created, viewed, and edited through direct picotiral manipulation.
Abstract: Provides a brief overview of the Act formalism, including a BNF grammar specification of Act.
D. E. Wilkins and K. L. Myers,
"A common knowledge representation for plan generation and reactive execution,"
Journal of Logic and Computation, vol. 5, number 6, pp. 731--761, December 1995.
Abstract: The ability to integrate sophisticated planning techniques with reactive execution systems is critical for nontrivial applications. Merging these two technologies is difficult because the forms of knowledge and reasoning that they employ differ substantially. The ACT formalism is a language for representing the knowledge required to support both the generation of complex plans and reactive execution of those plans in dynamic environments. A design goal of ACT was its adequacy for practical applications. ACT has been used as the interlingua in an implemented system that links a previously implemented planner with a previously implemented executor. This system has been used in several applications, including robot control and military operations, thus attesting to its expressive and computational adequacy.