What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, z will drive a car if and only if z will climb a mountain. For all z, z is not a taxi driver. For all z, z is a taxi driver if and only if z will drive a car. For all z, if z climbs a mountain, then z is driving a car.
For all z, if z drives a car, then z is climbing a mountain. For all z, if z were a taxi driver, then z is driving a car. For all z, if z climbs a mountain, then z is driving a car. For all z, if z drives a car, then z is a taxi driver. For all z, z will not drive a car.