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: Robert is not driving a car. If Mary were fast, then Mary is working. Robert is driving a car or Mary is a police officer. For all x_28, if x_28 were a police officer, then x_28 is fast.
Mary is a police officer can be inferred via the disjunctive syllogism rule. If Mary were excited, then Robert is driving a car can be inferred via the rewriting rule.