Let A be a countable subset of [0,1]. Denote the set of accumulation points of A by A'. Can the set of accumulation points of A' be nonempty (i.e. can we have that A'' is nonempty)?
Thanks for your help
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It only takes a minute to sign up.Sign up to join this community