Could someone please help me on this proof?
Find a statement form, S, equivalent to -(P V Q) and show that it is logically equivalent by constructing the truth table for "S if and only if -(P V Q)" and showing that this statment form is a tautology.
A tautology for -(P V Q) is -P^-Q and a tautology for -P V -Q is -(P ^ Q)
P Q -P ^-Q -P ^-Q
T T I'm not sure what the last two columns would be. Could someone please explain it to me?
The statement would be "If and only if she gets good grades she can go to the movies
Thank you very much