An exercise from the book A Mathematical Introduction to Logic

[GreenApple]

Homework Statement

you are in a land inhabinated by people who either always tell the truth or always tell falsehoods. You come to a fork in the road and you need to know which fork leads to the capital. There is a local resident there, but he has time only to reply to one yes-or-no question. What one question should you ask so as to learn which fork to take?
suggestion: Make a table.

Homework Equations

The Attempt at a Solution

If I asked you 'does the right way lead to the capital?', would you anwser 'yes'?
If the guy reply yes, take the right way. If no, the left.

I am wondering if I am surposed to ask questions about 'future' here?
What exactly does the writer mean by 'make a table'?

 

[HallsofIvy]

That's a perfectly good answer. As far as "make a table", I suspect it refers to having two columns, whether the right or fork is correct, and two rows, whether the person tells the truth or lies, when considering what results a specific question would get.

 

[tacman]

The question you proposed is a good one to ask in this scenario. It is important to note that you are not supposed to ask questions about the future, as that would not be a logical approach. The key is to come up with a question that will give you a definite answer, regardless of whether the person always tells the truth or always lies.

As for the suggestion to make a table, this means creating a logical table or chart to map out all the possible scenarios and their outcomes. This can help you come up with a question that will guarantee you the correct answer. For example, you could list all the possible answers the person could give (yes, no, maybe) and then think about what each of those answers would mean in terms of which fork to take. This can help you narrow down the best question to ask.