(if (eq (car plist) property)
(setplist symbol (cdr (cdr plist)))
(while (and (nthcdr 2 plist)
- (eq (car (nthcdr 2 plist)) property))
+ (not (eq (car (nthcdr 2 plist)) property)))
(setq plist (nthcdr 2 plist)))
(if (nthcdr 2 plist)
(setcdr (cdr plist) (nthcdr 4 plist))))))