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On matrices with the Edmonds-Johnson property arising from bidirected graphs. (English) Zbl 1384.05107

Summary: In this paper we study totally half-modular matrices obtained from \(\{0, \pm 1 \}\)-matrices with at most two nonzero entries per column by multiplying by 2 some of the columns. We give an excluded-minor characterization of the matrices in this class having strong Chvàtal rank 1. Our result is a special case of a conjecture by A. M. H. Gerards and A. Schrijver [Combinatorica 6, 365–379 (1986; Zbl 0641.05039)]. It also extends a well known theorem of J. Edmonds and E. L. Johnson [Math. Program. 5, 88–124 (1973; Zbl 0281.90073)].

MSC:

05C50 Graphs and linear algebra (matrices, eigenvalues, etc.)
90C10 Integer programming
90C27 Combinatorial optimization
Full Text: DOI

References:

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