DeMorgan's Laws

• ! ( exp1 && exp2 ) == ( ! exp1 || ! exp2 )

• ! ( exp1 || exp2 ) == (! exp1 && ! exp2 )

• ! ( a < 12 && b >= 18) == (a >= 12 || b < 18)

• ! ( c == d && e != f) == ( c != d || e == f)

• Practice: alternate.cpp in inclass