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https://issues.apache.org/jira/browse/RYA-295?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16119046#comment-16119046
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ASF GitHub Bot commented on RYA-295:
------------------------------------
Github user asfgit commented on the issue:
https://github.com/apache/incubator-rya/pull/201
Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/incubator-rya-master-with-optionals-pull-requests/373/
> Implement owl:allValuesFrom inference
> -------------------------------------
>
> Key: RYA-295
> URL: https://issues.apache.org/jira/browse/RYA-295
> Project: Rya
> Issue Type: Sub-task
> Components: sail
> Reporter: Jesse Hatfield
> Assignee: Jesse Hatfield
>
> An *{{owl:allValuesFrom}}* restriction defines the set of resources for
> which, given a particular predicate and other type, every value of that
> predicate is a member of that type. Note that there may be no values at all.
> For example, the ontology may state that resources of type {{:Person}} have
> all values from {{:Person}} for type {{:parent}}: that is, a person's parents
> are all people as well. Therefore, a pattern of the form {{?x rdf:type
> :Person}} should be expanded to:
> {noformat}
> { ?y rdf:type :Person .
> ?y :parent ?x }
> UNION
> { ?x rdf:type :Person }
> {noformat}
> i.e. we can infer {{?x}}'s personhood from the fact that child {{?y}} is
> known to satisfy the restriction.
> Notes:
> -We can infer "x is a person, therefore all of x's parents are people". But
> we can't infer "all of x's parents are people, therefore x is a person",
> because of the open world semantics: we don't know that the parents given by
> the data are in fact all of x's parents. (If there were also a cardinality
> restriction and we could presume consistency, then we could infer this in the
> right circumstances, but this is outside the scope of basic allValuesFrom
> support.) This differs with most other property restriction rules in that we
> can't infer that an object belongs to the class defined by the restriction,
> but rather use the fact that an object is already known to belong in that
> class in order to infer something about its neighbors in the graph (the types
> of the values).
> -The example above could be applied recursively, but to implement this as a
> simple query rewrite we'll need to limit recursion depth (and interactions
> with other rules, for the same reasons).
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