Setup and Rule Diagrams

[Adam Tyson]

The only problem with your contrapositives, jailenea , is that you have chosen to do a polar opposite instead of a logical opposite in your negation of "H G" and "K F". The polar opposite of H before G is G before H, but the logical opposite is "H is NOT before G." So if H is not before G, then at least one of H and G must be out, and that should make more sense intuitively to you. The same would be true of the K/F rule.

So, for example, if G is first, then H is not before G, so one of them must be out, and it would have to be H. Or, if H is last, then it is not before G, so G would have to be out (and F would have to be first).

Otherwise, your approach, and the decision to diagram the contrapositives, is great!