When I visited the Knights and Liars Archipelago, one island I visited was called Liontruth. The tourism had a great influence on the island, so much that the knaves on the island spoke differently from most knaves. They didn't have to follow an alternating pattern, but could tell truths (like knights always do) and lie (like liars always do) in whatever pattern they wanted. The three types of inhabitants are indistinguishable by eye.

If a tourist thinks the local knaves alternate truths and lies how can a knave convince the tourist that he is not a knave?

How can a knave from this island prove himself in one statement without revealing whether he is lying or not?

How can a knight prove himself in one statement?

How can a liar prove himself in one statement?

What single statement can be said by either a knight or liar but not a knave?

A1: Knave says "I am a knave" twice. A knight could not make this statement at all, and since the statement is either true both times or false both times, a tourist would assume a liar said this, based on the assumption that knaves on Liontruth alternate truths and lies.

A2: Knave says "I am a liar." (unless this violates the "revealing he is lying" clause; I'm not clear on that)

A3, 4, & 5: N/A.  Every person I know meets the definition of knave as stated in this puzzle; namely, that they can tell truths and lies in whatever pattern they want.  There is no statement that a knight or liar could make that I could not utter as well.  Perhaps if the definition is modified or clarified, a more classic puzzle with unique solutions would result.

Posted by Bryan on 2004-12-07 19:31:55