Set Theoryhard
0:00.0

Let AnA_n be a sequence of subsets of a universal set U=[0,1]U = [0, 1] defined for each nNn \in \mathbb{N} (starting at 1) as follows: An=[0,12]A_n = [0, \frac{1}{2}] if nn is odd, and An=[12,1]A_n = [\frac{1}{2}, 1] if nn is even. Determine the symmetric difference of the limit superior and limit inferior of this sequence, defined as (lim supnAn)Δ(lim infnAn)(\limsup_{n \to \infty} A_n) \Delta (\liminf_{n \to \infty} A_n), where lim supnAn=k=1n=kAn\limsup_{n \to \infty} A_n = \bigcap_{k=1}^{\infty} \bigcup_{n=k}^{\infty} A_n and lim infnAn=k=1n=kAn\liminf_{n \to \infty} A_n = \bigcup_{k=1}^{\infty} \bigcap_{n=k}^{\infty} A_n.