Sirpac examples

Hi,

 I use SirPac parser. I can't understand the result of its 7th example. The rdf file is as following:
<?xml version="1.0"?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:NIST="http://www.nist.gov/RDFschema/"
     xmlns:m="http://www.w3.org/TR/REC-MathML#">
  <Description about="http://www.some.org/publication.html">
    <NIST:Title rdf:ParseType="Literal">Investigations of <m:mathml>e=m<m:sup>2</m:sup></m:mathml></NIST:Title>
  </Description>
</RDF>

The parsed result is as following:

triple("http://www.nist.gov/RDFschema/Title","http://www.some.org/publication.html","Investigations of").
triple("http://www.w3.org/1999/02/22-rdf-syntax-ns#type","file:example7.rdf#genid2","http://www.w3.org/TR/REC-MathML#mathml").
triple("[DATA: e=m]","file:example7.rdf#genid2","file:example7.rdf#genid3").
triple("http://www.w3.org/TR/REC-MathML#sup","file:example7.rdf#genid2","2").
triple("http://www.nist.gov/RDFschema/Title","http://www.some.org/publication.html","file:example7.rdf#genid2").

The "Title" property of resource http://www.some.org/publication.html has two values. one is "Investigation" , the other is "file:example7.rdf#genid2). Is it reasonable in real world? How does the rdf parser work?

Thanks a lot if anybody could help me.

Ruan Tong