Regneregler vs. tautologier
((A � B)� C) � ((A � C) � (B � C))
������ ((A � B) � C) � (A � (B � C))
������ ((A � B) � C) � ((A � (B � C))
��������������� �(A � B) � (� A � � B)
(A � B)� C = (A � C) �(B�
� C)
(A � B) � C = A � (B � C)
(A � B) � C = (A � (B � C)
(A � B)� = (A� � B�)