Conforti, MicheleDi Summa, MarcoEisenbrand, FriedrichWolsey, Laurence A.2010-12-022010-12-022010-12-02200910.1287/moor.1080.0354https://infoscience.epfl.ch/handle/20.500.14299/61769WOS:000263602400012We consider mixed-integer sets described by system of linear inequalities in which the constraint matrix A is totally unimodular; the right-hand side is arbitrary vector; and a subset of the variables is required to be integer. We show that the problem of checking nonemptiness of a set of this type is NP-complete, even in the case in which the linear system describes mixed-integer network flows with half-integral requirement on the nodes.mixed-integer programmingcompact extended formulationstext::journal::journal article::research article