What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x, x will climb a mountain or x will play a game. There is at least one x for which if x climbs a mountain, then x is writing a letter. For all x, x will write a letter if and only if x will play a game.
For all x, if x writes a letter, then x is playing a game. For all x, if x plays a game, then x is writing a letter.