Covering a supermodular-like function in a mixed hypergraph.

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Bibliographic Details
Title: Covering a supermodular-like function in a mixed hypergraph.
Authors: Gao, Hui1 (AUTHOR) gaoh1118@yeah.net
Source: Discrete Applied Mathematics. May2026, Vol. 385, p72-76. 5p.
Subjects: Matroids, Hypergraphs, Set functions, Directed graphs, Combinatorial optimization, Submodular functions
Abstract: In this paper, we solve a conjecture by Szigeti in [Matroid-rooted packing of arborescences], which characterizes mixed hypergraphs F = (V , E ∪ A) for which there exists an orientation E ⃗ of E such that e E ⃗ ∪ A (P) ≥ ∑ X ∈ P h (X) − b (∪ P) for every subpartition P of V , where h is an integer-valued, intersecting supermodular function on V and b a submodular function on V. As a corollary, another conjecture in the same paper is confirmed, which characterizes mixed hypergraphs admitting a packing of mixed hyperarborescences such that their roots form a basis in a given matroid, each vertex v belongs to exactly k of them and is the root of at least f (v) and at most g (v) of them. [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
Description
Abstract:In this paper, we solve a conjecture by Szigeti in [Matroid-rooted packing of arborescences], which characterizes mixed hypergraphs F = (V , E ∪ A) for which there exists an orientation E ⃗ of E such that e E ⃗ ∪ A (P) ≥ ∑ X ∈ P h (X) − b (∪ P) for every subpartition P of V , where h is an integer-valued, intersecting supermodular function on V and b a submodular function on V. As a corollary, another conjecture in the same paper is confirmed, which characterizes mixed hypergraphs admitting a packing of mixed hyperarborescences such that their roots form a basis in a given matroid, each vertex v belongs to exactly k of them and is the root of at least f (v) and at most g (v) of them. [ABSTRACT FROM AUTHOR]
ISSN:0166218X
DOI:10.1016/j.dam.2026.01.023