Default Reasoning in Action Domains with Conditional, Non-Local Effect Actions

In a recent paper [2], Baumann et al. provided a comprehensive framework for default reasoning in action theories. Yet, the approach was only defined for a very basic class of domains where all actions have only unconditional, local effects. In this paper, we show that the framework can be substantially extended to domains with action effects that are conditional (i.e. are context-sensitive to the state in which they are applied) and non-local (i.e. the range of effects is not pre-determined by the action arguments). Notably, these features can be carefully added without sacrificing important nice properties of the basic framework, such as modularity of domain specifications or the existence of default extensions. In the last part of the paper, we demonstrate how (a subclass of) the framework can be straightforwardly implemented using the answer set programming paradigm.