A note on mixed graphs and directed splitting off
Steffen Enni · Journal of Graph Theory · 1998
We give counterexamples to two conjectures of Bill Jackson in Some remarks on arc-connectivity, vertex splitting, and orientation in graphs and digraphs (Journal of Graph Theory 12(3):429–436, 1988) concerning orientations of mixed graphs and splitting off in digraphs, and prove the first conjecture in the (di-) Eulerian case(s). Beside that we solve a degree constrained non-uniform directed augmentation problem for di-Eulerian mixed graphs. © 1998 John Wiley & Sons, Inc. J Graph Theory 27: 213–221, 1998