Recognizing Totally Dual Integral Systems is Hard
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چکیده
These are notes about Ding, Feng and Zang’s proof [5]. The proof of their result is not new, the only difference with them is the starting point: we work directly on their gadget graph encoding a SAT problem and not on more general graphs. This allows to shortcut some parts of the original proof that become superfluous. After proving their theorem I clarify some points about total dual integrality in order to put forward some remaining interesting open problems.
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