What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one z_4 for which z_4 will play a game if and only if z_4 is happy. For all z_4, z_4 will not play a game. For all z_4, if z_4 were a sailor, then z_4 is happy.
There is at least one z_4 for which if z_4 plays a game, then z_4 is happy. There is at least one z_4 for which if z_4 were happy, then z_4 is playing a game. There is at least one z_4 for which z_4 is not happy.