Esther is engaged. Her fiancé is either Arthur, Barton, Claude, or Dexter.
- Each of the four men and Esther is a knight or a liar.
- Arthur says: "Exactly one of us four men is a knight."
- Barton says: "Exactly one of us four men is a liar."
- Claude says: "Arthur or Barton is Esther’s fiancé."
- Esther says: "My fiancé and I are either
both knights, or both of us are liars."
Who is Esther's fiancé?
(In reply to
computer solution by Charlie)
It is more complicated than I thought.
No doubt, I have erred . But there is a serious flaw in your(= computer'S) solution.
- Each of the four men and Esther is a knight or a liar.
It is logical to assume an exclusive or, while you leave
"Esther's standing" open, contradictory to the text.