A Connectedness Puzzle (This is a point-set topology puzzle. For definitions of the terms involved, see any elementary topology text.) Our puzzle takes place in the unit square S = [0,1] x [0,1] in the plane. Take the midpoints of the edges P1 = (1/2,0) , P2 = (1/2,1) , Q1 = (0,1/2) and Q2 = (1,1/2). Can you find two disjoint connected subsets K and L of S, such that K contains P1 and P2, and L contains Q1 and Q2? If not, prove it can't be done.