Amin Mousavi - Electrical Engineering Group, Faculty of Engineering, University of Hormozgan, Bandar Abbas,Hormozgan, Iran
Parviz Jabedar-Maralani - Control &Intelligent Processing Center of Excellence, Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran.

In this paper, based on the mathematical definition of bilattices, a set theoretic bilattice structure is presented. This structure is an extension of the classical set theory to the pairs of sets equipped with two orderings. One is an extension of the classical set inclusion ordering and the other is a new ordering which is called knowledge ordering. The concepts and foundations of data mining based on the classical set theory are extended based on this structure, accordingly.