U. Hustadt and A. Nonnengart (1993): ``Modalities in Knowledge Representation.'' In C. Rowles, H. Liu, and N. Foo, editors, Proceedings of the 6th Australian Joint Conference on Artificial Intelligence (AI'93) [Melbourne, Australia, 16-19 November 1993], pp. 249-254. World Scientific, Singapore.
Abstract, BibTeX, PDF (© World Scientific).

Standard knowledge representation systems are supposed to be able to represent either common or individual knowledge about the world. In this paper we propose an extension to such knowledge representation systems which, in a uniform manner, allows to express beliefs of multiple agents as well as knowledge, desire, time and in fact any modality which has a first-order predicate logic possible world semantics.