符号非异矩阵的S＊—开拓

S *-matrix and Sign Nonsingular Matrix

198 4年 ,V .Klee ,R .Lander,R .Manber给出了一个对角元全负的SNS阵A可开拓为S 阵的一个充分条件 ,但是这个充分条件不是必要的 .在此将给出一个对角元全负的SNS阵可开拓为S 阵的若干充要条件 .这实际上也解决了ShaoJia yu和HwangSuk geun提出的关于nearlyL

The set of real matrices with the same sign pattern as A is called the qualitative class of A,denoted as Q (A).A square real matrix A is called a sign nonsingular matrix (abbreviated SNS matrix),if every matrix in Q (A) is nonsingular.Ais called an S * matrix,if each matrix obtained from A by deleting one of its columns is an SNS matrix.In this paper,we study the relationships between SNS matrix and S * matrix,sign solvable linear systems and sign solvable digraphs.And solvable an important special case of a problem about nearly L matrices proposed by Jia Yu Shao and Suk Geun Hwang.