Post #2589913

@simontatham@hachyderm.io It must be classical, because black is observing how white moves. The attack is not really happening afterwards, black is declaring that the board does not reflect the real state because they saw white pass a and attacked - the attack is not a killing from behind. There is one alternative though: white needs to declare an attempt before executing the move, black notes in hidden knowledge whether they attack if a is passed, then white flips a coin for the way.