A little assistance please!

@DonChris, Great question. Oliver could be the lowest ranking tennis player in this game board: G T M K P O S In the above game board, K is a floater and could be placed either before or after O or somewhere in the Golf category under L. This game board shows us that O can be the lowest-ranking tennis official, so we can eliminate this answer. Shigeru, however, can never be the lowest-ranking tennis player. We know this from the two rules that have to deal with M and S (and other players) The first rule says that if M is in G, then M-P-S in G, with M higher than P and P higher than S. M in G - >M - P - S The second rule says that if M is in T, then O-S-M in T, with O higher than S and S higher than M. M in T - >O - S - M This game can be split into boards in which M is in either G or T. If M is in G, then S can't even be a tennis player. However, when M is in T, then S must be between O and M. Because of this, S can never be the lowest-ranking tennis player. Does this make sense? Let us know if you have more questions!

I'm confused about the logic used to answer this question. Why is it assumed that M and S are playing tennis even though that is a conditional similar to that used for P and K? In rule 5 (Mt -> St), I thought that S being the necessary condition means that S could play tennis without M, which which would cause O to rank first and S to rank second if they were the only ones playing tennis. I also just recognized that the contrapositive of rule 5 means that M and S must both either play tennis or not play tennis, but I interpreted the contrapositive as Sg -> Mg.... is this uncalled for?