(N) +--------+ | 2 | N ∩ (not A or S) +----+ +----+ (S) | S ∩ N (2)|S ∩ N ∩ A(1) | +----+ +----+ +----+ | S (6) | S ∩ A (2)| S | | +----+ +--------+ A (0) | | 4 | A ∩ (not S or N) +--------+
