On Thu, 9 Aug 2007 23:06:04 +0200, you wrote:

Is still don't get it completely... Could you give me an extra hint? I'm getting crazy here, especially because I was really good at this stuff 20 years ago! :)

Here's the reasoning

The first answer could not be "no" because from that I can infer that John is a knight and Bill is a knave, which would mean the logician knows the answer.

This leaves me with 3 possibilities:

a) Both John and Bill are knights b) John is a knave and Bill could be anything

Correct. But you forgot to recursively apply the hint. ;) The problem states that after John answers the second question, the Logician knows the solution. How can this be? What answer did John give that allows the Logician to solve the problem? Steve Schafer Fenestra Technologies Corp. http://www.fenestra.com/