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 is cloudy, then it is cold. If it is cloudy, then it is cold. If it is cold, then it is cloudy. It is not cold.
It is not cloudy can be inferred via the modus tollens rule. It is not cloudy can be inferred via the modus tollens rule. It is cloudy if and only if it is cold can be inferred via the biconditional introduction rule. It is cloudy if and only if it is cold can be inferred via the biconditional introduction rule. It is cold if and only if it is cloudy can be inferred via the biconditional introduction rule. It is cold if and only if it is cloudy can be inferred via the biconditional introduction rule.