Truth teller with a twist

[bonanova]

How many twists can a classic have? This one occurred to me.

You're at a trisection, call the paths A B C, hungry, and headed for the diner, but which road leads there?
A jolly troll pops up and appears ready to assist you.
He is one of three types: truth teller, liar, one who randomly (coin toss) lies or tells the truth. (Not random yes/no.)
You ask him, will you answer truthfully any yes/no question that you can, responding with silence if you cannot?
His response is Yes.
Can you find the diner? if so, how many (more) questions are needed?
_________________
_{Vidi, vici, veni.}

[Thok]

But you haven't added in the "The troll speaks in trollish, and you don't remember if za and zo are trollish for yes and no or vice versa" trick.

[bonanova]

[bgg1996]

If he knows where the diner is and assists you in the regular fashion, you can find the diner in a single question.

Are an odd number of the following statements true:
* If I were to ask you in your current state of truth/falseness-tellinghood whether or not path A lead to the diner, you would say yes.
* If I were to ask you in your current state of truth/falseness-tellinghood whether or not path B lead to the diner, you would say yes, AND you are going to answer "YES" to this question.

Then again, if he does indeed answer any question that he can, you can come up with a much more fun solution.

Are an odd number of the following statements true:
* If you are currently in a state of truth-telling, you will answer NO to this question; otherwise, you will answer YES to this question.
* You will be my slave forever.
Now simply command your troll slave to carry you to the diner.
_________________
The one member below 18

[Zag]

[lostdummy]

[Zag]

I'm sure that you can word the question with a double negative, so that liars and truthtellers will give the same responses. The hole, here, is whether or not you can count on a liar (or a random in lying mode) to remain silent if there is no way to speak without uttering a truth. Knowing that is your assumption, he would effectively be lying by misleading you, even though the answer that he gave is strictly true.

But I like bgg's solution, where you end up with the troll as your slave.

[DejMar]

A reply to the question would be the same as making the material conditional statement: "(I) will respond in silence if (I) will not answer truthfully any yes/no question (I am) able." In order for this material conditional statement to be logically FALSE is if the respondant were to respond in silence AND if the respondant would answer truthfully any yes/no question he were able. Thus a liar would answer truthfully if he were able (of course he is unable) but would do so in silence. A truth teller would not respond in silence as doing so would be the same as a FALSE statement overall. Yet, not being silent, but responding with an answer of NO to the question would be just as TRUE for the overall statement. Nonetheless, the troll did respond with YES. As for one who randomly responds with the truth or a lie, the same possible verbal responses as the truth teller ("YES" or "NO") or the non-verbal silence of the liar can still be expected from the troll. As the troll did respond with a YES, all that can be deduced is that the troll is not the liar, though if he were one who randomly lied, he might still do so..
A question that is phrased properly may exist in which either the truth or a lie would provide the same correct answer. Though I have not determined this particular question, theoretically the answer to that of the puzzle's question in the number of questions needed is one.