public PNode(string plMt, SIProlog prolog, Graph data)
 {
     this.prologEngine = prolog;
     this.id           = plMt;
     prolog.KBGraph.AddNode(this);
     prologEngine.GraphForMT[plMt] = this;
     prologEngine.RegisterHomeGraph(data.BaseUri.AbsoluteUri, data, true);
     pdb = new PDB(true);
     pdb.RegisterRuleList(this);
     pdb.startMt        = plMt;
     pdb.followedGenlMt = false;
     PrologKB.id        = plMt;
     _rdfGraph          = data;
     EnsureGraphPrefixes(rdfGraph);
 }