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Reasoning with Multi-version Ontologies: a temporal logic approach. Zhisheng Huang and Heiner Stuckenschmidt Vrije University Amsterdam The Netherlands (ISWC05 paper). Outline. Motivation Framework Temporal logics Examples Prototype of MORE (Multi-version Ontology REasoner)
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Reasoning with Multi-version Ontologies: a temporal logic approach Zhisheng Huang and Heiner Stuckenschmidt Vrije University Amsterdam The Netherlands (ISWC05 paper) http://sekt.semanticweb.org/
Outline • Motivation • Framework • Temporal logics • Examples • Prototype of MORE (Multi-version Ontology REasoner) • Data Test and Evaluation • Conclusion and Future work. http://sekt.semanticweb.org/
Multi-versioning: Why • Change Recovery: allow the possibilities for the developers to withdraw or adjust the changes to avoid unintended impacts. • Compatibility: Ontology users may prefer an earlier version with less resource requirement to a newer version with higher resource requirement. • …… http://sekt.semanticweb.org/
The Idea of Versioning • Version Spaces: • Models resulting from changes are stored separately • Models and change operations form a graphcalled Version Space • Data is accessed through the “right” version v4 v2 v5 v3 v1 v6 http://sekt.semanticweb.org/
Managing Version Spaces • Idea: Enable Administrator to ask questions about the version space • Combine Reasoning: • Ontologies: DL reasoner (RACER) • Version Space: Modal Logic • Principle: • Each Ontology is a possible world • Truth of statements in a state is determine by the DL reasoner http://sekt.semanticweb.org/
Abstract Use Cases • Semantic Change Log (Temporal logic) • Summary of changes in the deductive closure • Compatibility Checking (Temporal logic) • Compare results of queries against expected answers • Version Selection (Hybrid Logic) • Check versions for certain required statements • Version Planning (Dynamic Logic) • Simulate the impact of possible changes http://sekt.semanticweb.org/
Simplifying Assumptions • Linear Time Temporal Logic • Linear Version Space • Operators • Conjunction, Negation, PreviousVersion, AllPriorVersions • Pre-defined Statement predicates • Child-of, parent-of, • Any other RACER function.. http://sekt.semanticweb.org/
Version Space • Version space: A version space S over an ontology set Os is a set of ontology pairs, namely, S Os × Os. • Linear version space: S = {<o1, o2>, <o2, o3>, · · · , <on−1, on>} such that oioj for i j. alternatively, we write S=(o1, o2, …, on) • Linear ordering: o < o’ iff o’ occurs prior to o in the sequence S. http://sekt.semanticweb.org/
Linear Time Logic LTLm • Operators: • Boolean operators: negation, conjunction, etc. • Temporal operators (Backlooking operators) • Prev : holds in the previous version • P: holds in a prior version(Sometimes in the past) • H: holds in all prior versions (Always in the past) • S: always holds in the prior versions since holds in a prior version http://sekt.semanticweb.org/
Linear Time Logic LTLm(F) • Operators: • Temporal operators (forward-looking operators) • Next : holds in the next version • F : holds in a sequel version(Sometimes in the future) • G: holds in all sequel versions (Always in the future) • U : always holds in all of the sequel versions until holds. http://sekt.semanticweb.org/
Semantics http://sekt.semanticweb.org/
Semantics • S, o |= Prev iff <o’, o> S and S, o’ |= . • S, o |= H iff o’< o and S, o’ |= . • S, o |= S iff o1, …, on (<o1, o2>, …,<on-1, on> S and on=o and S, oi |= and S, o1|= http://sekt.semanticweb.org/
Formal Properties • H -> P . • H -> Prev . • Prev -> Past . • Prev P -> P . • P P -> P . • H H -> H . • Prev Prev -> P . http://sekt.semanticweb.org/
Reasoning Queries • : holds in the current version • Prev : holds in the current version but no in the previous version. • P: incompactible (with respect to ). • H : holds only in the current version, it never holds before. http://sekt.semanticweb.org/
Reasoning Query: stable change • Once is changed, it is never changed again. S (H). http://sekt.semanticweb.org/
Change Accounting: Only Twice • is changed only twice. S Prev( SH). http://sekt.semanticweb.org/
Change Accounting: Only N times • Change(1, ) =df S H. • Change(n, ) =df S Prev(Change(n-1,)). http://sekt.semanticweb.org/
Reasoning Query: last version I • holds at the last version in which holds . S (Prev( )) http://sekt.semanticweb.org/
Reasoning Query: last version II holds at the last version in which does not hold before a version holds. S (Prev( S Prev( ))). http://sekt.semanticweb.org/
Retrieval Queries • child, parent concept relation http://sekt.semanticweb.org/
Relative Versioning • Version0 . (the current version) • Version-i Prev(Version-(i-1) ) http://sekt.semanticweb.org/
Absolute Versioning • Version(i,S) Versioni-n • where |S|=n http://sekt.semanticweb.org/
Retrieval Query http://sekt.semanticweb.org/
The MORE System • Milestone 3.5 – Software Prototype • . • Prototype: MORE (Multi-version Ontology REasoner) • MORE website: http://wasp.cs.vu.nl/sekt/more http://sekt.semanticweb.org/
An Extended DIG Description Logic Interface for Prolog (XDIG) • A logic programming infrastructure for the Semantic Web • Similar to SOAP • Application independent, platform independent • Support for DIG clients and DIG servers. http://sekt.semanticweb.org/
XDIG • As a DIG client, the Prolog programs can call any external DL reasoner which supports the DIG DL interface. • As a DIG server, the Prolog programs can serve as a DL reasoner, which can be used to support additional reasoning processing, like inconsistency reasoning multi-version reasoning, and inconsistency diagnosis and repair. http://sekt.semanticweb.org/
XDIG package • The XDIG package and the source code are now available for public download at the website: http://wasp.cs.vu.nl/sekt/dig/ • In the package, we offer five examples how XDIG can be used to develop extended DL reasoners. http://sekt.semanticweb.org/
The MORE System • Functionality • Temporal Reasoning Queries • Ontology Comparison Queries: • Versioning Retrieval Queries • Ontology Data format: OWL and DIG • Test Data • BioSAIL ontologies (3 versions) • SEKT legal case study ontologies (5 versions) http://sekt.semanticweb.org/
Test Result: Change Log http://sekt.semanticweb.org/
Conclusions • A framework of multi-version ontology reasoning • Temporal logic approach • Expressive power of LTLm • Semantic differences on multi-version ontologies. http://sekt.semanticweb.org/
Future Work • Integrating MORE with ontology evolution (Dynamic logic approach). • Hybrid logic approach for nominals • Branching time version space. • Merging time model (merging multiple ontologies). http://sekt.semanticweb.org/