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