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 cold, then it is snowing. It is cloudy or Barbara is not drinking water. If it snows, then it is cold.
If it is cloudy, then it is snowing can be inferred via the transitivity rule. If Barbara drinks water, then it is cloudy can be inferred via the rewriting rule. It is cold if and only if it is snowing can be inferred via the biconditional introduction rule. It is snowing if and only if it is cold can be inferred via the biconditional introduction rule.