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: For all x_7, x_7 is a janitor and x_7 is sad. There is at least one x_7 for which x_7 will go running if and only if x_7 is poor. For all x_7, if x_7 were poor, then x_7 is not a janitor.
For all x_7, x_7 is a janitor can be inferred via the universal simplification rule. For all x_7, x_7 is sad can be inferred via the universal simplification rule. There is at least one x_7 for which if x_7 goes running, then x_7 is poor can be inferred via the existential biconditional elimination rule. There is at least one x_7 for which if x_7 were poor, then x_7 is running can be inferred via the existential biconditional elimination rule.