Single Comment

1) Why not use '(checkmated King)' in the loss-condition?
   '(captured King)' allows to ignore checks.

2) When a checkmate by a regular move occurs the checkmated player can
   answer with an illegal move, and if this illegal move will result
   in a checkmate he will win, contrary to your remark (rule side)
   'Note that you cannot play an illegal move to escape from 
   checkmate, because checkmate ends the game immediately.'

   Try the following example (White to move): 
       White: Kh8, Rf1, Ng7, Ph7;
       Black: Ka8, Rg2, Pa7, Pb7.
   Now 1. Rf1-f8#  should end the game (result 1-0),
   but the zrf allows 1... Rg2xf8#  (result 0-1)

Alfred Pfeiffer  (apfde@yahoo.de)