Weare concerned with the implications and interactions of three commonexpressive extensions to classical planning: conditional plans, context-dependent actions, and nondeterministic action outcomes.All of these extensions have appeared in recent work, sometimes in conjunction, but the semantics of the combination has not beenfully explored. Aswehave argued in previous work, providing a coherent semantics for conditional planning with context-dependent actions requires that the planner's information state be modelled separately fromthe worldstate. In this paper, wepresent a newplanning language, WCPL,encompassing these extensions. The semantics of WCPL includes an explicit treatment of the planner's information state as knowledge, as opposedto someform of context labelling. In addition to clarifying and unifying a disparate set of results fromearlier work,we extend that work: WCPLhandles both conditional andfail-safe plans for an action representationincluding both context-de...
Robert P. Goldman, Mark S. Boddy