Panel

area-container<%>
      |
 panel:single<%>     window<%>
      |                 |
      +--------+--------+
               |
     panel:single-window<%>

• panel:single<%>
• panel:single-mixin
• panel:single-window<%>
• panel:single-window-mixin
• panel:single% = (panel:single-mixin (panel:single-window-mixin panel%))
• panel:single-pane% = (panel:single-mixin pane%)