You know the answer, Snail, and you have read that my friend left the details to me (which well he could; if this were serious rather than a "game", I would have been more cautious and meticulous).

Remains the question whether we enjoy such "games". I do to some degree, but only once in a while. This one will last for the rest of this year. In fact I must confess generally that a part of my personality enjoys discussing details, whereas the larger part strongly objects to the negligence of more important problems. I cannot really complain about lack of genuine challenges for my mental muscles; posting to Mudcat may amount to escapism altogether. One of my excuses is that it is a good training for my proficiency in English.

Some training in mathematics and logic has a great practical value as well: it helps us to be not so quickly convinced by apparent "common sense", neither by others nor by ourselves.