Collapsible Pushdown Graphs of Level 2 are Tree-Automatic
Logic in Computer Science
2015-07-01 v2 Formal Languages and Automata Theory
Logic
Abstract
We show that graphs generated by collapsible pushdown systems of level 2 are tree-automatic. Even if we allow epsilon-contractions and reachability predicates (with regular constraints) for pairs of configurations, the structures remain tree-automatic whence their first-order logic theories are decidable. As a corollary we obtain the tree-automaticity of the second level of the Caucal-hierarchy.
Keywords
Cite
@article{arxiv.1303.2453,
title = {Collapsible Pushdown Graphs of Level 2 are Tree-Automatic},
author = {Alexander Kartzow},
journal= {arXiv preprint arXiv:1303.2453},
year = {2015}
}
Comments
Journal version of arXiv:0912.4110, accepted for publication in LMCS