conditional statements

[Dr.Peterson]

I take your point but also note that the original sentence says "To be a citizen of this country,..." so it would also be necessary to consider that the speaker/writer might not actually be in the US at the time of speaking/writing but actually in another country altogether, however, a quick Google search convinces me that US citizenship alone would not be sufficient to gain citizenship in any other country.

First, please note the point I made, that this question is not about whether the statements are true in the real world, but only whether they are equivalent.

But you're right that the original statement assumes, presumably, that the statement is made in the U.S. ("this country"); that, too, is a problem I often see in this sort of assignment, where there is more than logic in the given statement.

The intervening posts were TLDR so I would just change my rendition to:-

b) If you were born in the United States then that is sufficient to be a citizen of that country.

or

b) If you were born in the United States then that is all you need to be a citizen of that country.​

Beyond that response, I have totally lost interest.

Of course, this is not a restatement in the form "if P then Q" as was required, as practice in logical terminology; it is just rewording the English..

But I, too, am done with the discussion; I just wanted to make sure some important things have been said, for the sake of other readers.

 

[logistic_guy]

@Dr.Peterson

I know that you decided to opt not replying to this thread. But at least give this post a LIKE if it's a part of your main point.

Original sentence: I will remember to send you the address only if you send me an email message.

Sending the email here is a must (necessary) for remembering. In other words, this sentence means: If you don't send me an email, I won't remember to send the address.

The debating sentence: If you send me an email message, then I will remember to send you the address.

Sending the email here is sufficient for remembering. In other words, the sentence means: If you send the email, I may remember to send the address.

So I think that your main point about a lie or not a lie is that sufficient to remember in the debating sentence doesn’t imply anything about what happens if the email isn't sent. And this is the main point (or the reason) why it's not equivalent to the original sentence.

 

[Dr.Peterson]

Original sentence: I will remember to send you the address only if you send me an email message.

Sending the email here is a must (necessary) for remembering.

This is true.

Filling out what you say here, because it's easy to confuse the email address and the email message, you are saying

Sending the email [message] is a must (necessary) for remembering [to send the address].​

"Only if" means that the only time he will remember to send the address is when the message is sent (without reference to timing or causality). So if he remembers, we can know that the message is sent . Remembering to send the address implies sending the email.

The debating sentence: If you send me an email message, then I will remember to send you the address.

Sending the email here is sufficient for remembering.

This claim about sufficiency is true, but this statement is the wrong answer.

In other words, this sentence means: If you don't send me an email, I won't remember to send the address.

No. This new sentence is the inverse of your "debating sentence", not equivalent to it; it's the contrapositive of "If I remember to send you the address then you send me an email message", and therefore equivalent to the correct answer.

In other words, the sentence means: If you send the email, I may remember to send the address.

This is wrong. First, the word "may" removes all the meaning, as no implication remains! Second, if you remove "may", the statement "If you send the email, then I remembered to send the address" is incorrect. This, again, is the converse of the intended statement.

So I think that your main point about a lie or not a lie is that sufficient to remember in the debating sentence doesn’t imply anything about what happens if the email isn't sent. And this is the main point (or the reason) why it's not equivalent to the original sentence.

I'm not sure I follow the grammar here. Neither the original sentence nor the "debating sentence" contains the word "sufficient", if that is what you are talking about.

My head is spinning with all the different sentences, so I hope I haven't slipped somewhere. I don't think bringing in "necessary" and "sufficient" makes the discussion any clearer, because those are easily misunderstood as well.