@ARTICLE{BrinkBritzSchmidt94, AUTHOR = {Brink, C. and Britz, K. and Schmidt, R. A.}, YEAR = {1994}, TITLE = {Peirce Algebras}, JOURNAL = {Formal Aspects of Computing}, VOLUME = {6}, NUMBER = {3}, PAGES = {339--358}, NOTE = {Also available as Technical Report MPI-I-92-229, Max-Planck-Institut f{\"u}r Informatik, Saarbr{\"u}cken, Germany (July 1992), and as Research Report RR 140, Department of Mathematics, University of Cape Town, Cape Town, South Africa (August 1992). An extended abstract appears in Nivat, M., Rattray, C., Rus, T. and Scollo, G. (eds), {\em Algebraic Methodology and Software Technology (AMAST'93): Proceedings of the Third International Conference on Algebraic Methodology and Software Technology}. {\em Workshops in Computing} Series, Springer, London, 165--168 (1994).}, ABSTRACT = {We present a two-sorted algebra, called a {\em Peirce algebra}, of relations and sets interacting with each other. In a Peirce algebra, sets can combine with each other as in a Boolean algebra, relations can combine with each other as in a relation algebra, and in addition we have both a set-forming operator on relations (the Peirce product of Boolean modules) and a relation-forming operator on sets (a cylindrification operation). Two applications of Peirce algebras are given. The first points out that Peirce algebras provide a natural algebraic framework for modelling certain programming constructs. The second shows that the so-called {\em terminological logics} arising in knowledge representation have evolved a semantics best described as a calculus of relations interacting with sets.} URL = {http://www.cs.man.ac.uk/~schmidt/publications/BrinkBritzSchmidt94.html}, }