Title
Tree Automata and Pigeonhole Classes of Matroids: I
Abstract
Hliněný’s Theorem shows that any sentence in the monadic second-order logic of matroids can be tested in polynomial time, when the input is limited to a class of $${\mathbb {F}}$$ -representable matroids with bounded branch-width (where $${\mathbb {F}}$$ is a finite field). If each matroid in a class can be decomposed by a subcubic tree in such a way that only a bounded amount of information flows across displayed separations, then the class has bounded decomposition-width. We introduce the pigeonhole property for classes of matroids: if every subclass with bounded branch-width also has bounded decomposition-width, then the class is pigeonhole. An efficiently pigeonhole class has a stronger property, involving an efficiently-computable equivalence relation on subsets of the ground set. We show that Hliněný’s Theorem extends to any efficiently pigeonhole class. In a sequel paper, we use these ideas to extend Hliněný’s Theorem to the classes of fundamental transversal matroids, lattice path matroids, bicircular matroids, and $$H$$ -gain-graphic matroids, where H is any finite group. We also give a characterisation of the families of hypergraphs that can be described via tree automata: a family is defined by a tree automaton if and only if it has bounded decomposition-width. Furthermore, we show that if a class of matroids has the pigeonhole property, and can be defined in monadic second-order logic, then any subclass with bounded branch-width has a decidable monadic second-order theory.
Year
DOI
Venue
2022
10.1007/s00453-022-00939-7
Algorithmica
Keywords
DocType
Volume
Matroid theory, Tree automata, Monadic second-order logic
Journal
84
Issue
ISSN
Citations 
7
0178-4617
0
PageRank 
References 
Authors
0.34
12
3
Name
Order
Citations
PageRank
Funk Daryl100.34
Dillon Mayhew210218.63
Newman Mike300.34