Reference:
http://reports-archive.adm.cs.cmu.edu/anon/1995/CMU-CS-95-113.pdf
http://docs.jboss.org/drools/release/6.0.0.Final/drools-docs/html/HybridReasoningChapter.html#ReteOO
Reference:
http://reports-archive.adm.cs.cmu.edu/anon/1995/CMU-CS-95-113.pdf
http://docs.jboss.org/drools/release/6.0.0.Final/drools-docs/html/HybridReasoningChapter.html#ReteOO