<?xml version="1.0"?>

<!DOCTYPE rdf:RDF [
    <!ENTITY rdf  'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
    <!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>
    <!ENTITY demo 'http://jena.hpl.hp.com/demo#'>
]>

<rdf:RDF xmlns:rdf="&rdf;" 
         xmlns:rdfs="&rdfs;" 
         xmlns:demo="&demo;"
         xmlns="&demo;"
         >

    <demo:TransProp rdf:about="&demo;p" />
    
    <rdf:Description rdf:about="&demo;a">
        <p rdf:resource="&demo;b" />
    </rdf:Description>
    
    <rdf:Description rdf:about="&demo;c">
        <p rdf:resource="&demo;a" />
    </rdf:Description>
    
    <rdf:Description rdf:about="&demo;b">
        <p rdf:resource="&demo;d" />
    </rdf:Description>

</rdf:RDF>