anchor.diff:  // Character set.   Picks up the user specified character set, should it be present.
   //
   charSet
  -    : CHARSET_SYM WS* STRING WS* SEMI
  +    : CHARSET_SYM WS+ STRING WS* SEMI
       -> ^(CHARSET STRING)
       ;
   
  
positive.code: // Import.  Location of an external style sheet to include in the ruleset.
  //
  cssImport
      : IMPORT_SYM WS* cssImportLocation  (WS* medium (WS* COMMA WS* medium)*)? WS* SEMI
      -> ^(IMPORT cssImportLocation medium*)
      ;
      
  
negative.code: //          it belongs to the signified medium.
  //
  media
      : MEDIA_SYM WS+ medium (WS* COMMA WS* medium)* WS*
          LBRACE WS*
              (ruleSet WS*)*
          RBRACE
      -> ^(MEDIA_SYM medium+ ruleSet*)
      ;
  
  // ---------    
  