What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is windy, then Robert is a police officer. If Elisabeth were a server, then Elisabeth is sleeping. Elisabeth is a server or it is windy. Robert is a police officer if and only if Elisabeth is sleeping.
If Robert were a police officer, then Elisabeth is sleeping. If Elisabeth sleeps, then Robert is a police officer.