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_12 for which if x_12 takes a plane, then x_12 is a doctor. For all x_12, x_12 is a doctor if and only if x_12 will play squash. For all x_12, if x_12 works, then x_12 is a doctor. For all x_12, x_12 will work or x_12 will take a plane.
There is at least one x_12 for which x_12 is a doctor. For all x_12, if x_12 were a doctor, then x_12 is playing squash. For all x_12, if x_12 plays squash, then x_12 is a doctor.