Quote:
Originally Posted by Jasper84  PGood to have your mind that a|b=(not (a and b))
...
(A if then B) = A | (B | B) = A | (A | B).
...
Last one is not very clear to me yet. |
The middle expression reduces to "not (and and not-b)," which is exactly what we want for (mathematical) implication: the implication is true at all times unless the hypothesis (A) is true and the conclusion (B) is false.