# Not (a AND b) is true if either a or b is false.

Since we know logical AND can be expressed with only NOT and OR:

`a b !a||!b !(!a||!b) a&&b !(a&&b)`

0 0 1 0 0 1

0 1 1 0 0 1

1 1 0 1 1 0

1 0 1 0 0 1

Not (A AND B) is equivalent to Not A OR Not B.

So Not A is true if A is false, and Not B is true is B is false.

Therefore, if either A or B is false, Not (A AND B) is true.