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, 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].

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.

<!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>