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: Joseph is not working. Thomas is driving a car if and only if Joseph is working. Richard is running. Robert is bored if and only if Thomas is not driving a car.
Joseph is not working and Richard is running can be inferred via the conjunction rule. Richard is running and Joseph is not working can be inferred via the conjunction rule. If Thomas drives a car, then Joseph is working can be inferred via the biconditional elimination rule. If Robert were bored, then Thomas is not driving a car can be inferred via the biconditional elimination rule. If Joseph works, then Thomas is driving a car can be inferred via the biconditional elimination rule. If Thomas doesn't drive a car, then Robert is bored can be inferred via the biconditional elimination rule. Thomas is not driving a car can be inferred via the biconditional elimination rule.