Abstract
Since fuzzy relation equations were firstly proposed by Sanchez in 1976,researches about the theory and applications of fuzzy relation equations were widely reported. In spite of this, it is difficult to find reports about methods to obtain only the set of independent solutions (solutions that are not contained in the others). In this paper, based on the method of solution defined by Tsukamoto and Tashiro, we propose the Interval Method. Using Tsukamoto's method, the Mid-martix , that is constructed as an intermediate step to find the solutions, may include empty set and one of the solutions which are included in another. In order to obtain easily and simply the solutions which are non-inclusive to one anothe, We introduce a greater/less Comparison Sign into a coefficient matrix, which is called Sign Matrix.An exampe shows that the proposed Interval Method gives effective solutions of the equations. In addition, by examining the Sign Matrix T, it is easy to determine the existance or non-existance of solutions.
