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 Richard were bored, then James is not poor. James is poor. Richard is bored if and only if Sarah is playing squash. If Sarah doesn't play squash, then Elisabeth is a soldier.
Richard is not bored can be inferred via the modus tollens rule. If Richard were bored, then Sarah is playing squash can be inferred via the biconditional elimination rule. If Sarah plays squash, then Richard is bored can be inferred via the biconditional elimination rule.