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 for which z will write a letter if and only if z will play a game. For all z, z will play a game and z is a soldier.
For all z, z will play a game. For all z, z is a soldier. There is at least one z for which if z writes a letter, then z is playing a game. There is at least one z for which if z plays a game, then z is writing a letter.