Action Localness, Genericity and Invariants in STRIPS.
Norman Foo, Abhaya Nayak, Maurice Pagnucco, Pavlos Peppas, Yan Zhang · 1997
The STRIPS specification for actions, despite criticisms of its shortcomings, remains popular in implementations because of its simplicity and intuitive appeal. Lifschitz showed in his logical account of STRIPS that states can safely be represented as sets of ground atom, and this is our starting point. Our aim is to provide logical foundations for design heuristics and procedural implementations of STRIPS. In particular, we formalize the notions of `localness' in pre- and post-conditions of actions. This justifies and explicates the intuitions that underlie the diagrammatic reasoning typically used to design such conditions. A formal account is also given for `generic' actions that have parameters. We conclude with a method for extracting candidate action invariants that distinguishes between two kinds of inertia implied by the action specifications. 1 Introduction Among the earliest proposals for specifying actions is STRIPS, due to Fikes and Nilsson [Fikes and Nilsson 71] . STRIP...