Temporal Agent Programs

Abstract

The ``agent program'' framework introduced by Eiter, Subrahmanian and Pick (\textbf{Artificial Intelligence, 108(1-2), 1999}), supports developing agents on top of arbitrary legacy code. Such agents are continuously engaged in an \emph{``event occurs, think, act, event occurs''} cycle. However, this framework has two major limitations: (1) all actions are assumed to have no duration, and (2) all actions are taken now, but cannot be \emph{scheduled for the future}. In this paper, we present the concept of a ``temporal agent program'' (\tap for short) and show that using {\tap}s, it is possible to build agents on top of legacy code that can reason about the past and about the future, and that can make temporal commitments for the future now. We develop a formal semantics for such agents, extending the concept of a status set proposed by Eiter et al., and develop algorithms to compute the status sets associated with temporal agent programs. Last, but not least, we show how {\tap}s support classical negotiation methods (as well as some new ones) and classical auction methods (as well as some new ones). (Also cross-referenced as UMIACS-TR-99-51)