A logical equivalance is derived from Theorem,supply a reason for each step;
(pv~q)^(~pvq)
�ß(~q v p)^(~q v ~p) by_________
�ß ~q v(p ^ ~p) by_________
�ß ~q v c by_________
�ß ~q by_________
Therefore,(p v~q)^ (~p v ~q)�ß ~q.