Logical Equivalences for Implies
l(a ¨ b) =   (ùa û b)
l(a ¨ b) = ù(a ú ùb)

l(0 ¨ b) = 1
l(1 ¨ b) = b
l(a ¨ 0) = ùa
l(a ¨ 1) = 1