anchor.diff:      ;
     
   constructQuery
  -    : ^(CONSTRUCT constructTemplate* datasetClause* whereClause* solutionModifier)
  -    | ^(CONSTRUCT datasetClause* ^(WHERE groupGraphPattern*) solutionModifier)
  +    : ^(CONSTRUCT constructTemplate datasetClause* whereClause? solutionModifier)
  +    | ^(CONSTRUCT datasetClause* whereClause? solutionModifier)
       ;
   
   describeQuery
  
positive.code:     ;
      
  modify
      : ^(MODIFY ^(WITH iriRef) deleteClause* insertClause* usingClause* ^(WHERE groupGraphPattern))
      | ^(MODIFY deleteClause* insertClause* usingClause* ^(WHERE groupGraphPattern))
      ;
    
  deleteClause
  
negative.code:     ;
      
  iriRefOrFunction
      : ^(FUNCTION f=iriRef ^(ARG_LIST (a=argList)))
      | ^(FUNCTION f=iriRef)
      ;
  
  rdfLiteral
  