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 Jessica were a soldier, then David is a carpenter. David is not a carpenter. Jessica is a soldier or it is not cloudy. If David were a carpenter, then Jessica is a soldier.
Jessica is not a soldier can be inferred via the modus tollens rule. If it is cloudy, then Jessica is a soldier can be inferred via the rewriting rule. Jessica is a soldier if and only if David is a carpenter can be inferred via the biconditional introduction rule. David is a carpenter if and only if Jessica is a soldier can be inferred via the biconditional introduction rule.