What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Michael plays tennis, then Elisabeth is drinking water. David is playing a game if and only if Michael is playing tennis. If Elisabeth drinks water, then David is playing a game.
If Michael plays tennis, then David is playing a game. If David plays a game, then Michael is playing tennis. If Michael plays tennis, then David is playing a game.