anchor.diff:  
   constraint
       : e=brackettedExpression -> constraint(brackettedExpression={$e.st})
  -    | b=builtInCall -> constraint(expression={$b.st})
  -    | f=functionCall -> constraint(expression={$f.st})
  +    | b=builtInCall -> constraint(builtInCall={$b.st})
  +    | f=functionCall -> constraint(functionCall={$f.st})
       ;
   
   functionCall
  
positive.code: groupGraphPattern
      : ^(GROUP_GRAPH_PATTERN g=groupGraphPatternSub) -> groupGraphPattern(groupGraphPatternSub={$g.st})
      | ^(GROUP_GRAPH_PATTERN s=subSelect) -> groupGraphPattern(subselect={$s.st})
      | ^(GROUP_GRAPH_PATTERN GROUP_GRAPH_PATTERN) -> groupGraphPattern(attribute={"{ }"})
      ;
    
  groupGraphPatternSub
  
negative.code:  */
  tree grammar SparqlT; 
  
  options { 
  tokenVocab=Sparql; // reuse token types
  ASTLabelType=CommonTree; // $label will have type CommonTree
  output=template; //template;
  