3 papers
math.CO2026
Counting permutations avoiding two flat partially ordered patterns
Shiqi Cao, Huihua Gao, Sergey Kitaev +1
Partially ordered patterns (POPs) play an important role in the study of permutation patterns, providing a convenient framework for describing large families of classical patterns.…
math.CO2025
Packing spanning arborescences with extra large one
Hui Gao
The celebrated Nash-Williams and Tutte's theorem states that a graph contains edge disjoint spanning trees if and only if , where $$ν_{f}(G):=\min_{…
math.CO2024
Covering a supermodular-like function in a mixed hypergraph
Hui Gao
In this paper, we solve a conjecture by Szigeti in [Matroid-rooted packing of arborescences, submitted], which characterizes a mixed hypergraph $\mathcal{F}=(V, \mathcal{E} \cup \m…