In RDF and other binary relation languages (like object oriented languages and description logics), one typical way to represent that a binary relation holds in some context is to "reify" the relation-holding (sometimes called obtainment) in the context as an object with a binary relation between the obtainment and each the two relation arguments and a third binary relation between the obtainment and an object representing the context itself. The downside to this approach is the expressive ability of the language to describe the binary relation, especially in the case of description logics, is lost.

The motivation for context slices is to provide a logical pattern for encoding context information in standard RDF graphs that allows some of the expressiveness of OWL to be used in describing the relations that hold in contexts.

This is a generaliztion of the four dimensional ontology for fluents published in [Welty & Fikes, 2006].

Take for example the statement "Chris believes Sam is CEO of IBM". Say we already have nodes in some graph representing Sam and IBM.

We create, as shown in the diagram, the context c1 corresponding to Chris' belief, and two nodes representing Chris' belief about Sam and Chris' belief about IBM (shown as Sam@c1 and IBM@c1).

This allows us to represent ceoOf as a binary relation, which seems more natural, and it allows us to use the expressivity of OWL in more ways. We can say of the ceoOf relation that it has an inverse, hasCeo. In contrast, the reified obtainment approach has no "directionality" in relations, but rather represents the "roles" played by the arguments as binary relations to the obtainment.

We can express cardinality, e.g. a company may have only one CEO within a context. This axiom cannot be expressed in OWL for reified obtainments.

We can say that a relation is transitive or symmetric. Symmetry can be expressed in reified obtainments by using a single role for both arguments, but not transitivity.

We can express relation taxonomies in the usual way. This is tricky to do using reified obtainments, though it is possible.

Ontology(<http://example.org/ContextSlices>
  Annotation(owl:versionInfo "1.0"@en)
  Annotation(rdfs:label "Context slices ontology logical pattern"@en)

  Declaration(Class(cs:Context))
  DisjointClasses(cs:Context cs:ContextualProjection)
  Declaration(Class(cs:ContextualProjection))
  SubClassOf(cs:ContextualProjection ObjectAllValuesFrom(cs:hasContext cs:Context))
  SubClassOf(cs:ContextualProjection ObjectExactCardinality(1 cs:hasContext))
  SubClassOf(cs:ContextualProjection ObjectExactCardinality(1 cs:projectionOf))
  DisjointClasses(cs:ContextualProjection cs:Context)
  Declaration(ObjectProperty(cs:contextualProperty))
  ObjectPropertyDomain(cs:contextualProperty cs:ContextualProjection)
  ObjectPropertyRange(cs:contextualProperty cs:ContextualProjection)
  Declaration(ObjectProperty(cs:hasContext))
  FunctionalObjectProperty(cs:hasContext)
  ObjectPropertyDomain(cs:hasContext cs:ContextualProjection)
  Declaration(ObjectProperty(cs:projectionOf))
  FunctionalObjectProperty(cs:projectionOf)
  ObjectPropertyDomain(cs:projectionOf cs:ContextualProjection)
 )

In RDF/XML:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rdf:RDF [
  <!ENTITY owl "http://www.w3.org/2002/07/owl#">
  <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#">
  <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">
]>
<rdf:RDF xml:base=""
         xmlns:owl="&owl;"
         xmlns:rdf="&rdf;"
         xmlns:rdfs="&rdfs;"> 
  <owl:Ontology rdf:about="">
    <rdfs:label xml:lang="en">Context slices ontology logical  pattern</rdfs:label>
    <owl:versionInfo xml:lang="en">1.0</owl:versionInfo>
  </owl:Ontology>
  <owl:Class rdf:about="ContextualProjection">
    <rdfs:comment rdf:datatype="&xsd;string">A contextual projection or slice of an entity or event.  
The context defines the contextual extent of the slice.  If any relations hold in a context, they 
must be to other slices of the same context (there is no way to enforce this constraint in OWL).
    </rdfs:comment>
    <rdfs:subClassOf>
      <owl:Restriction>
        <owl:cardinality rdf:datatype="&xsd;nonNegativeInteger">1</owl:cardinality>
        <owl:onProperty rdf:resource="#hasContext"/>
      </owl:Restriction>
    </rdfs:subClassOf>
    <rdfs:subClassOf>
      <owl:Restriction>
        <owl:cardinality rdf:datatype="&xsd;nonNegativeInteger">1</owl:cardinality>
        <owl:onProperty rdf:resource="#projectionOf"/>
      </owl:Restriction>
    </rdfs:subClassOf>
    <rdfs:subClassOf>
      <owl:Restriction>
        <owl:allValuesFrom rdf:resource="Context"/>
        <owl:onProperty rdf:resource="#hasContext"/>
      </owl:Restriction>
    </rdfs:subClassOf>
    <owl:disjointWith rdf:resource="Context"/>
  </owl:Class>
  <owl:Class rdf:about="Context">
    <rdfs:comment rdf:datatype="&xsd;string">It is intended that this class  should be equated
with whatever class represents contexts, with possibly subclasses for different kinds 
such as BeliefContext, TemporalInterval, etc.</rdfs:comment>
    <owl:disjointWith rdf:resource="#ContextualProjection"/>
  </owl:Class>
  <owl:ObjectProperty rdf:about="#contextualProperty">
    <rdfs:comment rdf:datatype="&xsd;string">A property that holds in a  context.</rdfs:comment>
    <rdfs:domain rdf:resource="#ContextualProjection"/>
    <rdfs:range rdf:resource="#ContextualProjection"/>
  </owl:ObjectProperty>
  <owl:FunctionalProperty rdf:about="#hasContext">
    <rdf:type rdf:resource="&owl;ObjectProperty"/>
    <rdfs:comment rdf:datatype="&xsd;string">The relation from a  ContextualProjection to the context 
in which some property holds</rdfs:comment>
    <rdfs:domain rdf:resource="#ContextualProjection"/>
  </owl:FunctionalProperty>
  <owl:FunctionalProperty rdf:about="#projectionOf">
    <rdf:type rdf:resource="&owl;ObjectProperty"/>
    <rdfs:comment rdf:datatype="&xsd;string">The entity or event that a  context slice is a slice of.</rdfs:comment>
    <rdfs:domain rdf:resource="#ContextualProjection"/>
  </owl:FunctionalProperty>
</rdf:RDF>

<?xml version="1.0"?>
<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
    xmlns:cs="http://www.example.org/ContextSlices#"
    xmlns:owl="http://www.w3.org/2002/07/owl#"
    xmlns:daml="http://www.daml.org/2001/03/daml+oil#"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
  xml:base="http://www.example.org/ContextSlicesExample">

  <owl:Ontology rdf:about="">
    <rdfs:label xml:lang="en">Example of using context slices</rdfs:label>
    <owl:versionInfo xml:lang="en">1.0</owl:versionInfo>
  </owl:Ontology>
  <owl:Class rdf:ID="Company"/>
  <owl:Class rdf:ID="Person"/>
  <owl:Class rdf:ID="BeliefContext">
    <rdfs:subClassOf rdf:resource="http://www.example.org/ContextSlices#Context"/>
  </owl:Class>
  <owl:ObjectProperty rdf:ID="believedBy"/>
  <owl:ObjectProperty rdf:ID="ceoOf">
    <rdfs:subPropertyOf>
      <owl:ObjectProperty rdf:ID="contextualProperty"/>
    </rdfs:subPropertyOf>
  </owl:ObjectProperty>

  <Person rdf:ID="Sam"/>
  <Person rdf:ID="Chris"/>
  <Company rdf:ID="IBM"/>

  <BeliefContext rdf:ID="c1">
    <believedBy rdf:resource="#Chris"/>
  </BeliefContext>
  <cs:ContextualProjection rdf:about="#IBM$c1">
    <cs:hasContext rdf:resource="#c1"/>
    <cs:projectionOf rdf:resource="#IBM"/>
  </cs:ContextualProjection>
  <cs:ContextualProjection rdf:about="#Sam$c1">
    <cs:hasContext rdf:resource="#c1"/>
    <ceoOf rdf:resource="#IBM$c1"/>
    <cs:projectionOf rdf:resource="#Sam"/>
  </cs:ContextualProjection>
</rdf:RDF>

Welty, Chris and Richard E. Fikes. 2006. A Reusable Ontology for Fluents in OWL. In Bennet and Fellbaum, eds., Proceedings of the Fourth International Conference on Formal Ontology in Information Systems. IOS Press. See http://www.booksonline.iospress.nl/Content/View.aspx?piid=2209