We propose an approximation of the Possible Worlds Semantics (PWS) for action
planning. A corresponding planning system is implemented by a transformation of
the action specification to an Answer-Set Program. A novelty is support for
postdiction wrt. (a) the plan existence problem in our framework can be solved
in NP, as compared to Σ2P​ for non-approximated PWS of Baral(2000); and
(b) the planner generates optimal plans wrt. a minimal number of actions in
Δ2P​. We demo the planning system with standard problems, and
illustrate its integration in a larger software framework for robot control in
a smart home.Comment: 12th International Conference on Logic Programming and Nonmonotonic
Reasoning (LPNMR 2013