Xjyuk

If you had $200 cash on you right now, and I asked you if you had $100 on you, would the correct answer be yes (always/no matter what other conditions there are), no (always/no matter what other conditions there are), or it depends on the situation?

My answer would be "yes" (always), because if someone asked me if I had $100 because he/she wanted to borrow it (and I had more than $100), then my reply would be "yes." I asked this question before (before deleting it because it was off-topic) on another stack exchange, and most of the answers were "it depends on the situation." But, I cannot imagine how it could depend on the situation.

If "it depends" if I have $100, that doesn't even make sense to me? Either I have $100 or I don't. Is the response "it depends" wrong or is it a situation of semantics?

If someone wanted to know if I had exactly $100, then he/she could ask me if I had exactly $100.

If someone asks you if you have $100 and you in fact do have $100 then you are telling the truth.

The only way you could falsify that statement is if you do not have $100 which would mean you have less than that amount. It doesn't matter if you have more that $100.

Here is the question:

If you had $200, and I asked you if you had $100, would the correct answer be yes (always), no (always), or it depends on the situation?

I would agree with the OP. The answer is yes. Always. There is no lying involved.

I would say it depends on the situation. Specifically, it depends on whether the person asking you the question wants to know whether you have at least $100, or exactly $100. The question could literally mean either, and only the context can decide. The former situation is likely much more common, and includes the example you mention, in which the person wishes to borrow $100.

But consider a similar example. Suppose I tell you I have five coins in my pocket, and then I take one out and throw it away. How many coins do I have left in my pocket? Wouldn't you consider it odd if in fact I have nine, because I had ten to start with?

This is one of those cases where in order to understand the meaning of an utterance you need to judge the speaker's intention in making it. If I volunteer the information that I have five coins in my pocket, it is a reasonable presumption that I am intending to tell you exactly how many I have. But depending on the context, some other intention may be obvious. If we are standing in front of the entrance to some building that charges five coins for admission, then my saying "I have five coins in my pocket" would more likely express the intended meaning that I have enough money to afford the entrance fee, and hence that I have at least five.

This can be understood as an example of Grice's theory of conversational implicature. The speaker's intention may differ from the literal semantic meaning of a sentence, because the utterance needs to be interpreted by its audience in the light of the co-operative principle. In this case, the ambiguity in the question is resolved by what is relevant to the conversation. ("Be relevant" is one of the maxims of the co-operative principle.)

Your question is about lying by omission, and this requires that you define lying. The definition I use is a communication with the intent to deceive. Thus, whether or not you are lying is a function of your intent, more than the actual quantity of cash you have on your person.

Let's examine two cases. In the first, you have $200, and when asked you state no knowing full well that there is $200 in your wallet. In this case, yes, it is a lie.

But here's another circumstance. Let's say while transferring a $100 bill from your safe to your wallet, you accidentally grabbed a second one (they were brand new and stuck together). Now, when asked the question, if you reply yes, despite the fact that you have $200, you have not lied, omission or otherwise. This is because you committed a mistake and were not aware of this mistake. As your intention is to communicate your sincere belief, then this is simply not a lie.