anchor.diff:        e2=EXISTS 
         { ec = new ExistsCondition($e2); 
           $condition = ec; }
  -      specifiedConditionVariable 
  -      { ec.setVariable($specifiedConditionVariable.variable); }
  +      specifiedVariable 
  +      { ec.setVariable($specifiedVariable.variable); }
       //-> ^(EXISTS_CONDITION[$EXISTS] specifiedVariable2)
       | //(EXISTS LIDENTIFIER (RPAREN|COMMA)) =>
         e1=EXISTS
  
positive.code:       { $specifierExpression.setExpression($functionOrExpression.expression); }
      ;
  
  conditionSpecifier returns [SpecifierExpression specifierExpression]
      : SPECIFY
        { $specifierExpression = new SpecifierExpression($SPECIFY); }
        //disjunctionExpression
        entryRangeExpression
        { Expression e = new Expression(null);
          e.setTerm($entryRangeExpression.term);
          $specifierExpression.setExpression(e); }
      ;
  
  lazySpecifier returns [SpecifierExpression specifierExpression]
      : COMPUTE
        { $specifierExpression = new LazySpecifierExpression($COMPUTE); }
  
negative.code:       )?
      ;
  
  variable returns [Variable variable]
      : compilerAnnotations
        var
  