 In contrast to Teapots, Teapots &amp; Scissors (Case Four below) does not exemplify 31(b). Teapots &amp; Scissors has parts where 31(b) is not true: take any part that has just the scissors or just a part of the scissors in it, for example. But Teapots &amp; Scissors is not a minimal situation in which 31(b) is true.