What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_4, x_4 will climb a mountain if and only if x_4 will take a plane. There is at least one x_4 for which x_4 will climb a mountain if and only if x_4 will play squash. For all x_4, x_4 will not take a plane.
For all x_4, if x_4 climbs a mountain, then x_4 is taking a plane. There is at least one x_4 for which if x_4 climbs a mountain, then x_4 is playing squash. For all x_4, if x_4 takes a plane, then x_4 is climbing a mountain. There is at least one x_4 for which if x_4 plays squash, then x_4 is climbing a mountain. For all x_4, x_4 will not climb a mountain.