Consider the following premises. If Susan were a bartender, then Karen is taking a plane. For all z, z will play a game. Karen is taking a plane if and only if Susan is playing a game. Can we infer the following from them? Karen is not taking a plane.
 From the fact that for all z, z will play a game we can infer that for all z, z will play a game or z is a bartender. From the fact that for all z, z will play a game or z is a bartender we can infer that Susan is playing a game or Susan is a bartender. From the fact that Karen is taking a plane if and only if Susan is playing a game we can infer that if Susan plays a game, then Karen is taking a plane. Finally, from the fact that if Susan plays a game, then Karen is taking a plane, that if Susan were a bartender, then Karen is taking a plane, and that Susan is playing a game or Susan is a bartender we can infer that Karen is taking a plane, which contradicts that Karen is not taking a plane. Therefore, the answer is no.