Let Z: (~Px (~Px v Qx)) => (Qx v Px)
Change the connective => in the formula Z to v using the rule X => Y <=> ~Xv Y
Using Boolean algebra rules, calculate the logical value of the formula Z when
Px = 0, Qx = 0
when
Px = 1, Qx = 1
when
Px = 0, Qx = 1
when
Px = 1, Qx = 0