[color:"orange"]I never said the question doesn't count as question... I said the whole sentence is one question, and not two, as you stated.
"If A and B are different, is A a liar?" <- Is this one question or two?[/color]
That conditional question can be broken down into two separate questions that provide the same information (except the liar is not prevented from answering if the condition is not true);
'Are A and B different?' / 'Is A a liar?'
These could be better phrased such as;
"If I asked you 'does A tell the truth?', would you say yes?'
so that a liar and a truth teller would answer the same way.
[color:"orange"]-> Answer me this question: "If A and B are different?"[/color]
The fact that the condition is not phrased as a question doesn't change the fact that you can link several questions into one by using a conditional question. The example I gave (asking a question about a question) is valid, IMNSHO, since it is a straight yes/no question, rather than yes/no/'your condition is not true' and gives you one piece of information, rather than one or two (with the first impossible to lie about).
[color:"orange"]The only really misleading aspect I see is the "yes or no" questions: however, the fact that they are questions that can only be answered by yes or no, doesn't rule out they simply can't be answered.[/color]
Then why the methodical reasoning on the two guards / two doors riddle? Why not just ask;
'if the door on the right leads to paradise, is red your favourite colour?'
That would simplify the explanation, since you would not have to follow the logic of asking which door the other guard would point to, depending on whether you were talking to the liar or the truth teller.
[color:"orange"]Compare it to a paradox.[/color]
Why? It is not a paradox. It is a question of semantics; what counts as a valid yes/no question and if it is legitimate to phrase a question so that the inability to answer with yes or no still provides you with information the same as a yes/no question would (actually better, since a liar can not answer if a condition is false) and being able to answer gives you two pieces of information (confirming the condition and answering the question).
