Here is 28.11:
The proof on page 206 initially refers to separation order E(a,b). In the second paragraph, it supposes distinct points in E(a,c) - {a,b}. I am reading this on my own so I have no-one else to ask. I believe it should read E(a,b) - {a,b}. Am I correct?
It turns I believe that there is an error in the following proof as well. Here's 28.12:
The third line of the proof should read "q > p." The fourth line is correct.
There may be yet a third typo in section 28 in the proof of 28.14. The proof reads "...form a chain of connected sets whose union is K - {x,y}..."
Regardless, I am only asking for an answer to the question regarding theorem 28.11. Any comments regarding the other 2 proofs would be welcome but are not needed.
If I am correct, I hope this will be helpful for those who read General Topology in the future.
Yes. There is an error. Brian Scott confirmed this in the comments section.