A note on disjoint arborescences

Recently Kamiyama, Katoh, and Takizawa have shown a theorem on packing arc-disjoint arborescences that is a proper extension of Edmonds' theorem on disjoint spanning branchings. We show a further extension of their theorem, which makes clear an essential r^ole of a reachability condition played in the theorem. The right concept required for the further extension is "convexity" instead of "reachability."

• Type: Journal
• Year: 2010
• Where: COMBINATORICA
• Authors: Satoru Fujishige
• Keywords: Arc-disjoint Arborescences, COMBINATORICA 2010, Machine Learning, Proper Extension, Reachability Condition