What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_13, x_13 will go running if and only if x_13 is a janitor. There is at least one x_13 for which if x_13 goes running, then x_13 is a taxi driver. For all x_13, x_13 is a janitor if and only if x_13 will go running.
For all x_13, if x_13 goes running, then x_13 is a janitor. For all x_13, if x_13 were a janitor, then x_13 is running. For all x_13, if x_13 were a janitor, then x_13 is running. For all x_13, if x_13 goes running, then x_13 is a janitor.