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 it rains, then John is playing tennis. If it is windy, then John is not playing tennis. If Richard sleeps, then it is raining. Richard is sleeping.
It is raining can be inferred via the modus ponens rule. If Richard sleeps, then John is playing tennis can be inferred via the transitivity rule.