October 2017
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23 Reads
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1 Citation
Journal of Combinatorial Theory Series B
In this paper we study totally half-modular matrices obtained from (0,±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 Gerards and Schrijver It also extends a well known theorem of Edmonds and Johnson