1) subject-nodes
   Is mapped to a topic with a PSI and a Topic ID equal to the subject-uri
2) blank nodes
   are mapped to a topic without a PSI, a uuid will be generated as a Topic ID
3) relationships between subject-nodes and literals
   Are mapped to occurrences of the type <preffix:arc> with the datatype of the
   corresponding RDF datatype. When there is no one given, the datatype is set to xml:string.
4) relationships between subject-nodes and object-nodes
   Are mapped to assocations of the type <preffix:arc> with the roles
     *of the type http://isidorus/rdf2tm_mapping/subject with the player <subject-node>
     *of the type http://isidorus/rdf2tm_mapping/object with the player <object-node>
5) rdf:_n properties
   Are mapped to an assocation of the type http://isidorus/rdf2tm_mapping/listing with the roles
     *of the type http://isidorus/rdf2tm_mapping/subject with the player <subject-node>
     *roles of the type http://www.w3.org/1999/02/22-rdf-syntax-ns#_n with the player <_n:object-node>
   If the <_n:object-node> is a literal node, there has to be produced a topic (T) with the Topic ID
   <UUID> and no PSI corresponding.
   The topic (T) contains an occurrence with the value of the property-element and the type
   http://isidorus/rdf2tm_mapping/literal_occurrence (datatype corresponding to the datatype in RDF).
   Topic T is an instance of http://isidorus/rdf2tm_mapping/literal_topic.
6) rdf:li
   All rdf:li elements are transformed to rdf:_n elements starting by rdf_1 and incremented by
   everey iteration. If the content of a node is mixed (the node contains rdf:li and rdf:_n elements)
   there is no specail processing for the transformation of rdf:li to rdf:_n. so it is possible that
   there will be exist two or more items with the name rdf:_1.
7) rdf:parseType="Collection"
   This nodes are mapped to topics corresponding to the given resouce-nodes and an association
   of the type <preffix:arc> with the roles:
     *of the type http://isidorus/rdf2tm_mapping/subject with the player <subject-node>
     *roles of the type http://isidorus/rdf2tm_mapping/collectionItem with the player <object-node>
8) rdf:type
   Is mapped to an instanceOf association
9) rdfs:subClassOf
   Is mapped to a supertype-subtype association
10) rdf:ID/reification
    *rdf:ID on subject-nodes: the corresponding subject-nodes are "merged" and the arc
                              of the reifying node (B) is pointed to the object-node (C) directly
                              from the original node (A)
    *rdf:ID on properties: Generates all topics from the node-IDs, arc-names or creates uuids.
                           Additionally there is created an association of the
			   type http://isidorus/rdf2tm_mapping/reification with the roles:
			     * of the type rdf:subject and the player <subject-node>
			     * of the type http://isidorus/rdf2tm_mapping/reifier with theplayer <reifier-node>
                                  if there is no reifier node theri will be generated a topic with
                     		  the Topic ID <uuid>
			     * of the type rdf:predicate and the player <predicate-topic>