Question

Bolzano weierstrass theorem to find whether set1/n:n is a natural number has a limit point

Answer 1

Let {an} be a bounded sequence which is bounded in [a,b]. Let D={x∈[a,b] | [a,x] contains infintely many terms of {an}}, in which the predicate "[a,x] contains infintely many terms of {an}" can be transfered into a more rigorous manner, "{n|an∈[a,x]} is infinite."

Hence D={x∈[a,b]∣∣{n|an∈[a,x]} is infinite