论文部分内容阅读
A matrix whose entries are +,-, and 0 is called a sign pattern matrix. For a sign pattern matrix A, if A3=A, then A is said to be sign tripotent. In this paper, the characterization of the n by n(n≥2) sign pattern matrices A which are sign tripotent has been given out. Furthermore, the necessary and sufficient condition of A3=A but A2≠A is obtained, too.