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: There is at least one x_9 for which if x_9 were poor, then x_9 is cooking. For all x_9, x_9 will work. For all x_9, if x_9 works, then x_9 is running. For all x_9, x_9 will cook if and only if x_9 will go running.
For all x_9, x_9 will go running can be inferred via the universal modus ponens rule. For all x_9, if x_9 cooks, then x_9 is running can be inferred via the universal biconditional elimination rule. For all x_9, if x_9 goes running, then x_9 is cooking can be inferred via the universal biconditional elimination rule.