Outline Mathematics
Logic Problems

Knights and Knaves 3

Here's a problem to tackle:

On an island, the populace is of two kinds: knights and knaves. Knights always tell the truth, knaves always lie.

An islander - call him A - made a statement: "Either I am a knave or 2 + 2 = 5."

What can we conclude?

Solution

Solution

(In the applet below, click on the underlined omitted expressions. See what happens.)

// formulations

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at http://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

References

R. Smullyan, What Is the Name of This Book?, Simon & Schuster, 1978

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Outline Mathematics Logic Problems

Knights and Knaves 3

Solution

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at http://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

References

Outline Mathematics
Logic Problems