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: John is an artist and it is raining. Mary is driving a car if and only if Jennifer is a mechanic. Mary is not driving a car.
John is an artist can be inferred via the simplification rule. It is raining can be inferred via the simplification rule. If Mary drives a car, then Jennifer is a mechanic can be inferred via the biconditional elimination rule. If Jennifer were a mechanic, then Mary is driving a car can be inferred via the biconditional elimination rule. Jennifer is not a mechanic can be inferred via the biconditional elimination rule.