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: Charles is a taxi driver if and only if Michael is driving a car. If Elisabeth were a soldier, then Michael is not driving a car. Charles is a taxi driver or John is bored. If John were bored, then Michael is driving a car. If Elisabeth were not a soldier, then it is snowing.
If Charles were a taxi driver, then Michael is driving a car can be inferred via the biconditional elimination rule. If Michael drives a car, then Charles is a taxi driver can be inferred via the biconditional elimination rule.