What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: Mary is a soldier. Elisabeth is not driving a car. Elisabeth is driving a car if and only if Sarah is a police officer.
Mary is a soldier and Elisabeth is not driving a car can be inferred via the conjunction rule. Elisabeth is not driving a car and Mary is a soldier can be inferred via the conjunction rule. If Elisabeth drives a car, then Sarah is a police officer can be inferred via the biconditional elimination rule. If Sarah were a police officer, then Elisabeth is driving a car can be inferred via the biconditional elimination rule. Sarah is not a police officer can be inferred via the biconditional elimination rule.