Abstract
Some sufficient conditions ensuring that the subdirect sum of two weakly chained diagonally dominant matrices is in this class, are given. In particular, it is shown that the subdirect sum of overlapping principal submatrices of a weakly chained diagonally dominant matrix is also a weakly chained diagonally dominant matrix.
Acknowledgements
The authors are grateful to the referees and the editor Prof. Bojan Kuzma for their useful and constructive suggestions.
Notes
No potential conflict of interest was reported by the authors.