China.2005 Reasoning with Multi-version Ontologies: a temporal logic approach Zhisheng Huang and Heiner Stuckenschmidt Vrije

China.2005 http://sekt.semanticweb.org/

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)

• Data Test and Evaluation

• Conclusion and Future work.


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.

• ……


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

v1 v3

v2 v4

v6

v5


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


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


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..


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 oi oj for i j.alternatively, we write

S=(o1, o2, …, on)

• Linear ordering: o < o’ iff o’ occurs prior to o in the sequence S.


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


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.


Semantics


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|=


Formal Properties

• H -> P .

• H -> Prev .

• Prev -> Past .

• Prev P -> P .

• P P -> P .

• H H -> H .

• Prev Prev -> P .


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.


Reasoning Query: stable change

• Once is changed, it is never changed again.

S (H).


Change Accounting: Only Twice

is changed only twice.

S Prev( S H).


Change Accounting: Only N times

• Change(1, ) =df S H.

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


Reasoning Query: last version I

holds at the last version in which holds .

S (Prev( ))


Reasoning Query: last version II

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

S (Prev( S Prev( ))).


Retrieval Queries

• child, parent concept relation


Relative Versioning

• Version0 . (the current version)

• Version-i Prev(Version -(i-1) )


Absolute Versioning

•Version(i,S) Version i-n

where |S|=n


Retrieval Query


The MORE System

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


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.


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.


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.


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)


Test Result: Change Log


Conclusions

• A framework of multi-version ontology reasoning

• Temporal logic approach

• Expressive power of LTLm

• Semantic differences on multi-version ontologies.


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).

Documents

China.2005 Reasoning with Multi-version Ontologies: a temporal logic approach Zhisheng Huang and Heiner Stuckenschmidt Vrije