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 Karen is climbing a mountain. It is raining or Richard is sleeping. It is windy if and only if Richard is sleeping. Karen is not climbing a mountain.
It is not raining can be inferred via the modus tollens rule. If it is windy, then Richard is sleeping can be inferred via the biconditional elimination rule. If Richard sleeps, then it is windy can be inferred via the biconditional elimination rule.