anchor.diff:  // 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_SYM WS+ cssImportLocation  (WS+ medium (WS* COMMA WS* medium)*)? WS* SEMI
       -> ^(IMPORT cssImportLocation medium*)
       ;
       
  
positive.code: //          it belongs to the signified medium.
  //
  media
      : MEDIA_SYM medium (COMMA medium)*
          LBRACE
              ruleSet
          RBRACE
      ;
  
  // ---------    
  
negative.code:     ;   
      
  page
      : PAGE_SYM (WS+ COLON pseudoPage)? WS* LBRACE WS* (declaration WS*)* RBRACE
      -> ^(PAGE_SYM pseudoPage? ^(DECLARATION declaration)*)
      ;
  
  pseudoPage
      : IDENT
      ;
      
  combinator
  