anchor.diff:   (MAP-OVER-PRESENTATION-TYPE-SUPERTYPES . :function)
    (MAP-OVER-REGION-SET-REGIONS . :generic)
    (MAP-OVER-ROW-CELLS . :generic)
  - (MAP-OVER-ROW-CELLS . :generic)
    (MAP-OVER-SHEETS . :generic)
    (MAP-OVER-SHEETS-CONTAINING-POSITION . :generic)
    (MAP-OVER-SHEETS-OVERLAPPING-REGION . :generic)
  
positive.code:   t)
  
  (defmethod check-symbol (symbol (category (eql :presentation-type-abbrev)))
    t)
negative.code:  (FRAME-MANAGER-FRAMES . :generic)
   (FRAME-MANAGER-MENU-CHOOSE . :generic)
   (FRAME-MANAGER-NOTIFY-USER . :generic)
   (FRAME-MANAGER-P . :function)
   (FRAME-NAME . :generic)
   (FRAME-PANES . :generic)
   (FRAME-PARENT . :generic)
  