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_1 for which x_1 is a doctor. For all x_1, x_1 is an office clerk.
There is at least one x_1 for which x_1 is a doctor and x_1 is an office clerk. There is at least one x_1 for which x_1 is an office clerk and x_1 is a doctor.