Year: 2009
Type: preprint
Abstract: We show that graphs generated by collapsible pushdown systems of level 2 are tree-automatic. Even when we allow $ε$-contractions and add a reachability predicate (with regular constraints) for pairs of configurations, the structures remain tree-automatic. Hence, their FO theories are decidable, even when expanded by a reachability predicate. As a corollary, we obtain the tree-automaticity of the second level of the Caucal-hierarchy.
Source: arXiv (Cornell University)
Author: Kartzow, Alexander
Institution: Technische Universität Darmstadt
Language: English
Subfield: Computational Theory and Mathematics
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4302599485