prevent redundant LeftJoin evaluation on nodes which were previously marked as clashed.  'Activated' evaluation of empty triple patterns - for ex: LeftJoin({},X).  Added additional debugging statements
prevent redundant LeftJoin evaluation on nodes which were previously marked as clashed.  'Activated' evaluation of empty triple patterns - for ex: LeftJoin({},X).  Added additional debugging statements

Letractively/rdflib,Letractively/rdflib,Letractively/rdflib