What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Barbara goes running, then Elisabeth is driving a car. Karen is an office clerk if and only if Michael is a mechanic. Michael is not a mechanic. If Elisabeth drives a car, then Karen is an office clerk.
If Barbara goes running, then Karen is an office clerk. If Karen were an office clerk, then Michael is a mechanic. If Michael were a mechanic, then Karen is an office clerk. Karen is not an office clerk.