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 x_9 for which x_9 is an artist if and only if x_9 is a doctor. For all x_9, if x_9 plays squash, then x_9 is an artist. For all x_9, if x_9 climbs a mountain, then x_9 is playing squash. For all x_9, x_9 is a doctor or x_9 will climb a mountain.
For all x_9, if x_9 climbs a mountain, then x_9 is an artist. There is at least one x_9 for which if x_9 were an artist, then x_9 is a doctor. There is at least one x_9 for which if x_9 were a doctor, then x_9 is an artist.