The delta-sum of matching delta-matroids Original Research Article

We discuss a composition operation of delta-matroids, called delta-sum, in relation to similar compositions of related combinatorial structures like matroids and jump systems. The delta-sum of matching delta-matroids is associated with the linkings of a graph. We exhibit a min-max formula for the polyhedral rank function of that delta-matroid, which implies a result of Gallai on linkings.