tinyjo | It's a good puzzle but it can't possibly compete in difficulty (Reply)

...with some of the stuff towards the back of Raymond Smullyan's book previously mentioned. Some of the stuff in his book also relies on the characters being perfect logicians, absolute truth-tellers, and infallible observers - but he also mixes in knaves who always tell lies, normals who sometimes lie and sometimes tell the truth, mad knaves who think they are lying but actually tell the truth (and mad knights who lie equally inadvertently), and Tweedledee and Tweedledum who tell lies and truth on alternate days of the week (and both tell the truth on Sunday - the question is how to find out what weekday it actually is).