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: David is playing tennis. Susan is driving a car. If Michael were happy, then David is not playing tennis.
Michael is not happy can be inferred via the modus tollens rule. David is playing tennis and Susan is driving a car can be inferred via the conjunction rule. Susan is driving a car and David is playing tennis can be inferred via the conjunction rule.