Vertex disjoint cycles of different lengths in d-arc-dominated digraphs

Gao and Ma (2013) have proved that every 4-arc-dominated digraph contains two vertex disjoint directed cycles of different lengths. In this paper, by arguments similar to those used by Gao and Ma in the above-mentioned paper, we show that every d-arc-dominated digraph with d≥4 contains two vertex disjoint directed cycles of different lengths.