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https://issues.apache.org/jira/browse/RYA-294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16140103#comment-16140103
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ASF GitHub Bot commented on RYA-294:
------------------------------------
Github user ejwhite922 commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/217#discussion_r135021324
--- Diff:
sail/src/main/java/org/apache/rya/rdftriplestore/inference/SomeValuesFromVisitor.java
---
@@ -0,0 +1,110 @@
+package org.apache.rya.rdftriplestore.inference;
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+
+import org.apache.rya.api.RdfCloudTripleStoreConfiguration;
+import org.apache.rya.api.utils.NullableStatementImpl;
+import org.apache.rya.rdftriplestore.utils.FixedStatementPattern;
+import org.openrdf.model.Resource;
+import org.openrdf.model.URI;
+import org.openrdf.model.vocabulary.OWL;
+import org.openrdf.model.vocabulary.RDF;
+import org.openrdf.query.algebra.StatementPattern;
+import org.openrdf.query.algebra.Var;
+
+/**
+ * Expands the query tree to account for any existential class expressions
(property restrictions
+ * using owl:someValuesFrom) in the ontology known to the {@link
InferenceEngine}.
+ *
+ * Operates on {@link StatementPattern} nodes whose predicate is rdf:type
and whose object is a
+ * defined type (not a variable) which corresponds to a someValuesFrom
expression in the ontology.
+ * When applicable, replaces the node with a union of itself and a subtree
that matches any instance
+ * that can be inferred to have the type in question via the semantics of
owl:someValuesFrom.
+ *
+ * An existential class expression references a predicate and a value
class, and represents the set
+ * of individuals with at least one value of that class for that
predicate. Therefore, membership
+ * in the class expression should be inferred for any individual which is
the subject of a triple
+ * with that predicate and with an object belonging to the value type.
This implication is similar
+ * to rdfs:domain except that it only applies when the object of the
triple belongs to a specific
+ * type.
+ *
+ * (Note: The inference in the other direction would be that, if an
individual is declared to belong
+ * to the class expression, then there exists some other individual which
satisfies the requirement
+ * that there is at least one value of the appropriate type. However, this
other individual may be
+ * any arbitrary resource, explicitly represented in the data or
otherwise, so this implication is
+ * not used.)
+ */
+public class SomeValuesFromVisitor extends AbstractInferVisitor {
+ /**
+ * Creates a new {@link SomeValuesFromVisitor}, which is enabled by
default.
+ * @param conf The {@link RdfCloudTripleStoreConfiguration}.
+ * @param inferenceEngine The InferenceEngine containing the relevant
ontology.
+ */
+ public SomeValuesFromVisitor(RdfCloudTripleStoreConfiguration conf,
InferenceEngine inferenceEngine) {
+ super(conf, inferenceEngine);
+ include = true;
--- End diff --
A config value for SomeValuesFrom inferencing should be added to
RdfCloudTripleStoreConfiguration.
> Implement owl:someValuesFrom inference
> --------------------------------------
>
> Key: RYA-294
> URL: https://issues.apache.org/jira/browse/RYA-294
> Project: Rya
> Issue Type: Sub-task
> Components: sail
> Reporter: Jesse Hatfield
> Assignee: Jesse Hatfield
>
> An *{{owl:someValuesFrom}}* restriction defines the set of resources which,
> for a given predicate and other type, have at least one value of that other
> type for that predicate.
> If the ontology states that {{:Chair}} is the set of resources who are
> {{:headOf}} at least one resource which must itself be a {{:Department}},
> then:
> {{?x rdf:type :Chair}}
> should be expanded to:
> {noformat}
> { ?x :headOf ?dept .
> ?dept rdf:type :Department }
> UNION
> {?x rdf:type :Chair }
> {noformat}
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