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: It is windy if and only if Mary is playing tennis. If Mary plays tennis, then Michael is climbing a mountain. If it is cold, then it is windy. Michael is not climbing a mountain.
Mary is not playing tennis can be inferred via the modus tollens rule. If it is windy, then Mary is playing tennis can be inferred via the biconditional elimination rule. If Mary plays tennis, then it is windy can be inferred via the biconditional elimination rule.