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