From what I see in this thread, you say your spouse has no income at all for 2017, and therefore will not be filing a return at all, correct? Then all the conditions combined apply to you.
You were married at the end of 2017, your filing status is married filing separately or head of household,
This is true for you, since you're filing MFS
and both of the following apply. a. Your spouse had no income and isn't filing a return.
Yep, she has no income and is not filing a return.
b. Your spouse can't be claimed as a dependent on another person's return."
Yep, this is true too. Your spouse can't be claimed on anyone else's return.
If you and your spouse file separate returns,
The above is a bit oxy-moronic in it's wording, but still true for you.
you may claim the exemption for your spouse only if he or she had no gross income,
The above is true.
is not filing a joint return
The above is true.
and was not the dependent of another taxpayer."
and finally, that is true.
When it comes to IRS pubs, you have to interpret them "literally". When one starts reading between the lines that which is not there, it's easy to get confused. Add to that the oxy-moronic wording that can tend to make some things a "grey area" as evidenced by what you point out above, and it can be a real challenge to do that "literal" interpretation.
I find that by breaking it down to individual items as I did above, it makes it much easier to reach a conclusion that even a tax court would have a hard time disagreeing with, lord forbid should it ever come to that. Generally when you have a "grey area" like the one you point out, the tax court tends to side with the tax payer (that's you) and then the IRS has to revise their publication to provide the necessary clarification for the future. Things like this are happening all the time.
