What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, if x_9 were a lawyer, then x_9 is a doctor. For all x_9, if x_9 were a doctor, then x_9 is a lawyer. There is at least one x_9 for which if x_9 were a doctor, then x_9 is a lawyer.
For all x_9, x_9 is a lawyer if and only if x_9 is a doctor. For all x_9, x_9 is a doctor if and only if x_9 is a lawyer. There is at least one x_9 for which x_9 is a doctor if and only if x_9 is a lawyer. There is at least one x_9 for which x_9 is a lawyer if and only if x_9 is a doctor.