What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If William were a mechanic, then Jennifer is playing a game. If William were a taxi driver, then William is a mechanic. If Jennifer plays a game, then William is a taxi driver. William is not a mechanic.
William is not a taxi driver. If William were a mechanic, then William is a taxi driver. If William were a taxi driver, then Jennifer is playing a game. If Jennifer plays a game, then William is a mechanic.