Also, necessary and sufficient conditions for singularity of irreducible matrices are given in Chapter 1 according to three classes of G-pairs, by which nonsingularity criteria can be obtained easily.

• 在第一章我们还依据三类G-函数对给出了不可约矩阵奇异的充要条件，从而容易获得矩阵非奇异性的判别准则。