Not sure if it helps someone, but I like to use the following intermediate formula to explain it: "A implies B" is equivalent to "B or (not A)" (either B is tru

Not sure if it helps someone, but I like to use the following intermediate formula to explain it: "A implies B" is equivalent to "B or (not A)" (either B is true and then A can be true or false, or B is false but then A cannot be true since it would entail that B is true as well). "B or (not A)" is equivalent to "(not A) or B" and to "(not A) or (not (not B))", you can then apply the previous reasoning to realize it's also equivalent to "(not B) implies (not A)". Not sure if my twisted way of thinking about it helps anyone though... furthermore it requires to have clearly in mind the distinction between "or" and "xor", the later being sadly closer to the vernacular use of "or"...