Intellektik: Technical report 94-03
Disjunction in Resource-Oriented Ddeductive Planning
S. Brüning and S. Hölldobler and J. Schneeberger and U. C. Sigmund and M. Thielscher
To model in a formal system the remarkable ability of human agents to reason
about situations, actions, and causality has always been a major research goal
in Intellectics. Most of the work towards this goal is based on the situation
calculus which, however, has the disadvantage that it requires either to state
frame axioms or to use nonmonotic logic and a commonsense law of inertia.
Recently, three new deductive approaches were developed which do not show this
disadvantage. These are the linear connection method, an equational Horn
logic, and the linear logic. Their key idea is to treat facts about a
situation as resources which can be consumed and produced by actions. The
approaches are essentially equivalent for conjunctive planning problems, ie.
problems, where situations and conditions as well as effects of actions are
(non-idempotent) conjunctions of facts. In this paper we extend and revise the
equational logic approach and the linear connection method to handle also
disjunctions of facts. We show that these extended approaches and the approach
based on linear logic augmented by rules handling disjunction are equivalent
wrt. a unique semantic of disjunctive planning problems.