On dijoins

Abstract

For every nonnegative integer arc weight function w, the minimum weight of a dicut is at least as large as the maximum number of dijoins such that no arc a is contained in more than iv(o) of these dijoins. We give two examples of digraphs with strict inequality for some weight w and discuss the possibility that, together with an example due to Schrijver, these are the only "minimal" such examples. © 2002 Elsevier Science B.V.