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 snowing if and only if Karen is a janitor. It is snowing or it is cold. If Karen were a janitor, then it is windy. It is not windy.
Karen is not a janitor can be inferred via the modus tollens rule. If it snows, then Karen is a janitor can be inferred via the biconditional elimination rule. If Karen were a janitor, then it is snowing can be inferred via the biconditional elimination rule.