anchor.diff:  grammar Javadoc;
   
  -file : file_element*;
  +file : file_element* EOF;
   
   file_element
     : javadoc
  
positive.code: // |{@value}      | 1.4         |
  // |@version      | 1.0         |
  // +--------------+-------------+
    
  WS : [ \n\r\t\u000B\u000C\u0000]+ -> channel(HIDDEN);
  
negative.code: // Some of the tags below could contain other tags, thus using description
  // would be safe because description is the most comprehensive text 
  // representation in this grammar.
  standard_tags
    : standard_tag*
    ;
  