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: Mary is taking a plane if and only if Linda is playing tennis. Mary is not taking a plane. If it snows, then Linda is playing tennis. Linda is playing tennis or Mary is not taking a plane.
If Mary takes a plane, then Linda is playing tennis can be inferred via the rewriting rule. If Mary takes a plane, then Linda is playing tennis can be inferred via the biconditional elimination rule. If Linda plays tennis, then Mary is taking a plane can be inferred via the biconditional elimination rule. Linda is not playing tennis can be inferred via the biconditional elimination rule.