ILLEGAL: a f8-a3;won on turn 3:
There was no a on f8. The piece on f8 is a dh.
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For diagnostic purposes, here is the full movelist:
1. P e2-e4 
1... p f7-f6 
2. P b2-b3 
2... p e7-e5 
3. P d2-d4 
3... a f8-a3;won //Checkmate!
In case there is a bug in the code, the settings file can be edited at /play/pbm/play.php?game=Cetran+Chess+2&settings=asymmetric&submit=Edit