שינויים

<math>\left |p(A)\Delta p(B) \right |= \left |(A/B)\cup (B/A) \right |=\left |A/B \right |+\left | B/A \right |-\left | (B/A)\cap (A/B) \right |=\left | A \right |-\left | A\cap B \right |+\left | B \right |-\left | A\cap B \right |=2^{n}+2^{m}-2\cdot 2^{k}=2^{n}+2^{m}-2^{k+1}</math>