anchor.diff:      ;
       
   modify
  -    : ^(MODIFY ^(WITH iriRef) deleteClause* insertClause* usingClause* whereClause /*^(WHERE groupGraphPattern)*/)
  -    | ^(MODIFY deleteClause* insertClause* usingClause* whereClause /*^(WHERE groupGraphPattern)*/)
  +    : ^(MODIFY ^(WITH iriRef) deleteClause* insertClause* usingClause* whereClause)
  +    | ^(MODIFY deleteClause* insertClause* usingClause* whereClause)
       ;
     
   deleteClause
  
positive.code:     ;
  
  regexExpression
      : ^(REGEX (e+=expression)+) -> regexExpression(type={$REGEX.text}, expression={$e})
      ;
      
  subStringExpression
  
negative.code:     ;
      
  path
      : ^(PATH (p+=pathSequence)+) -> path(pathSequence={$p})
      ; 
  
  pathSequence
      : ^(PATH_SEQUENCE (p+=pathEltOrInverse)+) -> pathSequence(pathEltOrInverse={$p})
      ;
      
  pathEltOrInverse
  