Abstract
Our concern is the problem of determining the data complexity of answering an ontology-mediated query (OMQ)given in linear temporal logic LTL over (Z,<) and deciding whether it is rewritable to an FO(<)-query, possibly with extra predicates. First, we observe that, in line with the circuit complexity and FO-definability of regular languages, OMQ answering in AC0, ACC0 and NC1 coincides with FO(<,≡)-rewritability using unary predicates x ≡ 0(mod n), FO(<,MOD)-rewritability, and FO(RPR)-rewritability using relational primitive recursion, respectively. We then show that deciding FO(<)-, FO(<,≡)- and FO(<,MOD)-rewritability of LTL OMQs is ExpSpace-complete, and that these problems become PSpace-complete for OMQs with a linear Horn ontology and an atomic query, and also a positive query in the cases of FO(<)- and FO(<,≡)-rewritability. Further, we consider FO(<)-rewritability of OMQs with a binary-clause ontology and identify OMQ classes, for which deciding it is PSpace-, Πp 2- and coNP-complete.
Original language | English |
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Pages | 10:1-10:15 |
Publication status | Published - 2021 |
Event | 28th International Symposium on Temporal Representation and Reasoning - Klagenfurt, Austria Duration: 27 Sept 2021 → 29 Sept 2021 Conference number: 28 https://drops.dagstuhl.de/entities/volume/LIPIcs-volume-206 |
Conference
Conference | 28th International Symposium on Temporal Representation and Reasoning |
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Abbreviated title | TIME 2021 |
Country/Territory | Austria |
City | Klagenfurt |
Period | 27/09/21 → 29/09/21 |
Internet address |
Keywords
- linear temporal logic
- ontology-mediated query
- first-order rewritability