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 not snowing. It is raining if and only if Barbara is a politician. If Barbara were a politician, then it is snowing.
Barbara is not a politician can be inferred via the modus tollens rule. If it rains, then Barbara is a politician can be inferred via the biconditional elimination rule. If Barbara were a politician, then it is raining can be inferred via the biconditional elimination rule.