Parallel Hyperedge Replacement String Languages
Abstract
There are many open questions surrounding the characterisation of groups with context-sensitive word problem. Only in 2018 was it shown that all finitely generated virtually Abelian groups have multiple context-free word problems, and it is a long-standing open question as to where to place the word problems of hyperbolic groups in the formal language hierarchy. In this paper, we introduce a new language class called the parallel hyperedge replacement string languages, show that it contains all multiple context-free and ET0L languages, and lay down the foundations for future work that may be able to place the word problems of many hyperbolic groups in this class.
Keywords
Cite
@article{arxiv.2102.03164,
title = {Parallel Hyperedge Replacement String Languages},
author = {Graham Campbell},
journal= {arXiv preprint arXiv:2102.03164},
year = {2021}
}
Comments
In Proceedings TERMGRAPH 2020, arXiv:2102.01804. arXiv admin note: substantial text overlap with arXiv:2101.02310