scholarly journals Data Complexity and Rewritability of Ontology-Mediated Queries in Metric Temporal Logic under the Event-Based Semantics

2019 ◽  
Author(s):  
Vladislav Ryzhikov ◽  
Przemyslaw Andrzej Walega ◽  
Michael Zakharyaschev
Keyword(s):  
Temporal Logic ◽  
Transitive Closure ◽  
Order Logic ◽  
Data Complexity ◽  
Complexity Bounds ◽  
Metric Temporal Logic ◽  
First Order ◽  
Primitive Recursion ◽  
Lower Complexity ◽  
Event Based

We investigate the data complexity of answering queries mediated by metric temporal logic ontologies under the event-based semantics assuming that data instances are finite timed words timestamped with binary fractions. We identify classes of ontology-mediated queries answering which can be done in AC0, NC1, L, NL, P, and coNP for data complexity, provide their rewritings to first-order logic and its extensions with primitive recursion, transitive closure or datalog, and establish lower complexity bounds.

scholarly journals Ontology-Mediated Querying with the Description Logic EL: Trichotomy and Linear Datalog Rewritability

2017 ◽  
Author(s):  
Carsten Lutz ◽  
Leif Sabellek
Keyword(s):  
Description Logic ◽  
Order Logic ◽  
First Order Logic ◽  
Data Complexity ◽  
First Order ◽  
Fine Grained ◽  
Linear Recursion

We consider ontology-mediated queries (OMQs) based on an EL ontology and an atomic query (AQ), provide an ultimately fine-grained analysis of data complexity and study rewritability into linear Datalog-aiming to capture linear recursion in SQL. Our main results are that every such OMQ is in AC0, NL-complete or PTime-complete, and that containment in NL coincides with rewritability into linear Datalog (whereas containment in AC0 coincides with rewritability into first-order logic). We establish natural characterizations of the three cases, show that deciding linear Datalog rewritability (as well as the mentioned complexities) is ExpTime-complete, give a way to construct linear Datalog rewritings when they exist, and prove that there is no constant bound on the arity of IDB relations in linear Datalog rewritings.

A review of temporal logics

1989 ◽  
Vol 4 (2) ◽  
pp. 141-162 ◽  
Author(s):  
Derek Long
Keyword(s):  
Artificial Intelligence ◽  
Temporal Logic ◽  
Temporal Reasoning ◽  
Order Logic ◽  
First Order Logic ◽  
Temporal Logics ◽  
Detailed Review ◽  
First Order ◽  
Reasoning Tasks

AbstractA series of temporal reasoning tasks are identified which motivate the consideration and application of temporal logics in artificial intelligence. There follows a discussion of the broad issues involved in modelling time and constructing a temporal logic. The paper then presents a detailed review of the major approaches to temporal logics: first-order logic approaches, modal temporal logics and reified temporal logics. The review considers the most significant exemplars within the various approaches, including logics due to Russell, Hayes and McCarthy, Prior, McDermott, Allen, Kowalski and Sergot. The logics are compared and contrasted, particularly in their treatments of change and action, the roles they seek to fulfil and the underlying models of time on which they rest. The paper concludes with a brief consideration of the problem of granularity—a problem of considerable significance in temporal reasoning, which has yet to be satisfactorily treated in a temporal logic.

scholarly journals Querying Log Data with Metric Temporal Logic

2018 ◽  
Vol 62 ◽  
pp. 829-877 ◽  
Author(s):  
Sebastian Brandt ◽  
Elem Güzel Kalaycı ◽  
Vladislav Ryzhikov ◽  
Guohui Xiao ◽  
Michael Zakharyaschev
Keyword(s):  
Temporal Logic ◽  
Real World ◽  
Large Datasets ◽  
Weather Data ◽  
Data Complexity ◽  
Log Data ◽  
Metric Temporal Logic ◽  
Temporal Concepts ◽  
Horn Fragment ◽  
Typical User

We propose a novel framework for ontology-based access to temporal log data using a datalog extension datalogMTL of the Horn fragment of the metric temporal logic MTL. We show that datalogMTL is EXPSPACE-complete even with punctual intervals, in which case full MTL is known to be undecidable. We also prove that nonrecursive datalogMTL is PSPACE-complete for combined complexity and in AC0 for data complexity. We demonstrate by two real-world use cases that nonrecursive datalogMTL programs can express complex temporal concepts from typical user queries and thereby facilitate access to temporal log data. Our experiments with Siemens turbine data and MesoWest weather data show that datalogMTL ontology-mediated queries are efficient and scale on large datasets.

scholarly journals “Most of” leads to undecidability: Failure of adding frequencies to LTL

2021 ◽  
pp. 82-101
Author(s):  
Bartosz Bednarczyk ◽  
Jakub Michaliszyn
Keyword(s):  
Model Checking ◽  
Formal Verification ◽  
Temporal Logic ◽  
Order Logic ◽  
First Order Logic ◽  
Statistical Reasoning ◽  
First Order ◽  
High Interest ◽  
The Past ◽  
Influence Networks

AbstractLinear Temporal Logic (LTL) interpreted on finite traces is a robust specification framework popular in formal verification. However, despite the high interest in the logic in recent years, the topic of their quantitative extensions is not yet fully explored. The main goal of this work is to study the effect of adding weak forms of percentage constraints (e.g. that most of the positions in the past satisfy a given condition, or that $$\sigma $$ σ is the most-frequent letter occurring in the past) to fragments of LTL. Such extensions could potentially be used for the verification of influence networks or statistical reasoning. Unfortunately, as we prove in the paper, it turns out that percentage extensions of even tiny fragments of LTL have undecidable satisfiability and model-checking problems. Our undecidability proofs not only sharpen most of the undecidability results on logics with arithmetics interpreted on words known from the literature, but also are fairly simple. We also show that the undecidability can be avoided by restricting the allowed usage of the negation, and discuss how the undecidability results transfer to first-order logic on words.

Boolean Role Inclusions in DL-Lite With and Without Time

2020 ◽  
Author(s):  
Roman Kontchakov ◽  
Vladislav Ryzhikov ◽  
Frank Wolter ◽  
Michael Zakharyaschev
Keyword(s):  
Description Logic ◽  
Expressive Power ◽  
Necessary Condition ◽  
Data Complexity ◽  
Temporal Dimension ◽  
Complexity Level ◽  
Primitive Recursion ◽  
Lower Complexity ◽  
Computational Properties

Traditionally, description logic has focused on representing and reasoning about classes rather than relations (roles), which has been justified by the deterioration of the computational properties if expressive role inclusions are added. The situation is even worse in the temporalised setting, where monodicity is viewed as an almost necessary condition for decidability. We take a fresh look at the description logic DL-Lite with expressive role inclusions, both with and without a temporal dimension. While we confirm that full Boolean expressive power on roles leads to FO^2-like behaviour in the atemporal case and undecidability in the temporal case, we show that, rather surprisingly, the restriction to Krom and Horn role inclusions leads to much lower complexity in the atemporal case and to decidability (and ExpSpace-completeness) in the temporal case, even if one admits full Booleans on concepts. The latter result is one of very few instances breaking the monodicity barrier in temporal FO. This is also reflected on the data complexity level, where we obtain new rewritability results into FO with relational primitive recursion and FO with unary divisibility predicates.

scholarly journals First-Order Logic with Two Variables and Unary Temporal Logic

2002 ◽  
Vol 179 (2) ◽  
pp. 279-295 ◽  
Author(s):  
Kousha Etessami ◽  
Moshe Y. Vardi ◽  
Thomas Wilke
Keyword(s):  
Temporal Logic ◽  
Order Logic ◽  
First Order Logic ◽  
First Order
Sign in / Sign up

Export Citation Format

Share Document