goal area,box

The characterization and construction of minimal forbidden configuration(MFC) of strong sign nonsingular digraph (simplifed as S 2NS digraph) are concerned by many researchers.

强符号非异有向图 (简称S2 NS有向图 )的极小禁用子图 (简称MFC)的判定和构造等问题是众多学者所关心的问题 。