Difference labelling of digraphs
Martin Sonntag · Discussiones Mathematicae Graph Theory · 2004
A digraph G is a difference digraph iff there exists anFor some classes of digraphs, e.g.alternating trees, oriented cycles, tournaments etc., it is known, under which conditions these digraphs are difference digraphs (cf.[5]).We generalize the so-called sourcejoin (a construction principle to obtain a new difference digraph from two given ones (cf.[5])) and construct a difference labelling for the source-join of an even number of difference digraphs.As an application we obtain a sufficient condition guaranteeing that certain (non-alternating) trees are difference digraphs.