['stylesheet', 
  ['ruleset', 
    ['selector', 
      ['simpleselector', 
        ['clazz', 
          ['ident', 't']], 
        ['s', '
']]], 
    ['block', 
      ['s', '
        '], 
      ['filter', 
        ['property', 
          ['ident', 'filter']], 
        ['filterv', 
          ['progid', 
            ['raw', 'progid:DXImageTransform.Microsoft.Alpha(Opacity=40)'], 
            ['s', ' ']], 
          ['important']]], 
      ['decldelim'], 
      ['s', '
']]]]