Reasoning with Multiversion Ontologies: a temporal logic approach

1
Reasoning with Multi-version Ontologies a
temporal logic approach

• Zhisheng Huang and Heiner Stuckenschmidt
• Vrije University Amsterdam
• The Netherlands

2
Outline

• Motivation
• Framework
• Temporal logics
• Examples
• Prototype of MORE (Multi-version Ontology
  REasoner)
• Data Test and Evaluation
• Conclusion and Future work.

3
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.

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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
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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

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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..

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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 lto1, o2gt, lto2, o3gt,
  , lton-1, ongt such that oi ?oj for i? j.
• alternatively, we write
• S(o1, o2, , on)
• Linear ordering olt o iff o occurs prior to
  o in the sequence S.

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Linear Time Logic LTLm

• Operators
• Boolean operators negation, conjunction, etc.
• Temporal operators (Backlooking operators)
• Prev? ? holds in the previous version
  (PreviousVersion)
• P? ? holds in a prior version(Sometimes in the
  past) (SomePriorVersion)
• H? ? holds in all prior versions (Always in
  the past) (AllPriorVersions)
• ?S? ? always holds in the prior versions
  since ? holds in a prior version (Since)

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Semantics
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Formal Properties

• H ? -gt P ?.
• H ? -gt Prev ?.
• Prev ? -gt P?.
• Prev P ? -gt P ?.
• P P ? -gt P ?.
• H H ? -gt H ?.
• Prev Prev ? -gt P ?.

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Reasoning Queries

• ? ? holds in the current version
• ? ?? Prev ? ? holds in the current version but
  not in the previous version.
• ?? ?P? incompactible (with respect to ?).
• ? ? H?? ? holds only in the current version,
  it never holds before.

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Reasoning Query stable change

• Once ? is changed, it is never changed again.

?? S (H?).
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Change Accounting Only Twice

• ? is changed only twice.

?? S Prev(? S H??).
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Change Accounting Only N times

• Change(1, ?) df ?? S H?.
• Change(n, ?) df ?? S Prev(Change(n-1,??)).

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Reasoning Query last version I

• ? holds at the last version in which ? holds .

?? S (Prev(?? ?))
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Reasoning Query last version II

• ? holds at the last version in which ? does not
  hold before a version ? holds.

?? S (Prev(? S Prev(??? ?))).
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Retrieval Queries

• child, parent concept relation

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Relative Versioning

• Version0? ? ?. (the current version)
• Version-i? ? Prev(Version -(i-1) ?)

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Absolute Versioning

• Version(i,S)? ? Version i-n?
• where Sn

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Retrieval Query
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The MORE System

• Milestone 3.5 Software Prototype
• .
• Prototype MORE (Multi-version Ontology REasoner)
• MORE website http//wasp.cs.vu.nl/sekt/more

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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)

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A Query Answer
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Test Result Change Log
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Conclusions

• A framework of multi-version ontology reasoning
• Temporal logic approach
• Expressive power of LTLm
• Semantic differences on multi-version
  ontologies.

26
Future Work

• Integrating MORE with ontology evolution (Dynamic
  logic approach).
• Branching time version space.