The Object (3rd) part of a triple can have several different 
types. If the object is a resource it is returned as either a plain atom 
or a term NameSpace:Name. If it is a 
literal it is returned as literal(Value), where Value 
takes one of the formats defined below.
xml:lang qualifier.
lang(LanguageID, Atom)xml:lang qualifier
LanguageID specifies the language and Atom the 
actual text.
element(Name, Attributes, Content) and atoms for CDATA 
parts as described with the SWI-Prolog
SGML/XML 
parser.
type(Type, StringValue)rdf:datatype=Type a term 
of this format is returned.