anchor.diff:      | ^(IRI expression)
       | ^(URI expression)
       | ^(BNODE expression)
  +    | BNODE
       | RAND
       | ^(ABS expression)
       | ^(CEIL expression)
  
positive.code:     ;
  
  subSelect
      : ^(SUBSELECT whereClause* solutionModifier)
      ;
      	
  selectClause
  
negative.code: // $<Parser
  
  query
      : ^(QUERY prologue selectQuery? constructQuery? describeQuery? askQuery?) bindingsClause?
      | ^(UPDATE update+)
      ;
  
  