Turns out the conclusion is wrong! No wonder why i couldnt figure it out!
it should say
EXCEPT for at most a numerable number of .
Can any one make this a little bit more clear please?
Let be a metric space, and a probability measure on borel sets of E.
I do not understand the next implication:
for (at most) a numerable number of
is the topological boundary
I think i may be missing a "core" property of finite measures but i dont remember!
Thanx in advance
EDIT: Bad title i can't fix this sorry