anchor.diff:      ;
   
   serviceGraphPattern
  -    : SERVICE SILENT? varOrIRIref groupGraphPattern -> ^(SERVICE varOrIRIref groupGraphPattern)
  +    : SERVICE SILENT? varOrIRIref groupGraphPattern -> ^(SERVICE SILENT? varOrIRIref groupGraphPattern)
       ;
       
   bind
  
positive.code:     ;
  
  groupClause
      : GROUP BY (g+=groupCondition)+ -> ^(GROUPBY $g+)
      ;
      		 
  groupCondition
  
negative.code:     ;
    
  constructQuery
      : CONSTRUCT constructTemplate datasetClause* whereClause solutionModifier -> ^(CONSTRUCT constructTemplate datasetClause* whereClause* solutionModifier?)
      | CONSTRUCT datasetClause* WHERE OPEN_CURLY_BRACE triplesTemplate? CLOSE_CURLY_BRACE solutionModifier -> ^(CONSTRUCT datasetClause* ^(WHERE triplesTemplate*) solutionModifier?)
      ;
  
  describeQuery
      : DESCRIBE ( (v+=varOrIRIref)+ | ASTERISK ) datasetClause* whereClause? solutionModifier -> ^(DESCRIBE $v* ASTERISK* datasetClause* whereClause? solutionModifier?)
      ;
  
  askQuery
  