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: If Mary drives a car, then David is rich. David is not rich. Mary is driving a car or David is not rich.
Mary is not driving a car can be inferred via the modus tollens rule. If David were rich, then Mary is driving a car can be inferred via the rewriting rule.