Pebble-Intervals Automata and FO2 with Two Orders (Extended Version)

Autor:	Labai, Nadia, Kotek, Tomer, Ortiz, Magdalena, Veith, Helmut
Rok vydání:	2019
Předmět:	Computer Science - Logic in Computer Science
Druh dokumentu:	Working Paper
Popis:	We introduce a novel automata model, called pebble-intervals automata (PIA), and study its power and closure properties. PIAs are tailored for a decidable fragment of FO that is important for reasoning about structures that use data values from infinite domains: the two-variable fragment with one total preorder and its induced successor relation, one linear order, and an arbitrary number of unary relations. We prove that the string projection of every language of data words definable in the logic is accepted by a pebble-intervals automaton A, and obtain as a corollary an automata-theoretic proof of the EXPSPACE upper bound for finite satisfiability due to Schwentick and Zeume. Comment: This extended version includes proofs omitted from the LATA 2020 version
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1912.00171 Zobrazit plný text záznamu View this record from Arxiv