although I understand what limit is about I don't understand why the definition requires an interval like this
and not one like this:
when it wants to show that there exists the limit on the point p. How the second one would harm the limit definition?
Thank you in advance!
I understand, you mean it doesn't use the closed one because it wants to show that it is not interested on a, b themself but on those point going very close to p.
It seems logical, I just was afraid that might be something else that I missed out.
Thank you very much for making it clear.