What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_4, if x_4 sleeps, then x_4 is running. For all x_4, if x_4 plays squash, then x_4 is sleeping. For all x_4, if x_4 goes running, then x_4 is playing squash. Robert is not running.
For all x_4, if x_4 sleeps, then x_4 is playing squash. For all x_4, if x_4 plays squash, then x_4 is running. For all x_4, if x_4 goes running, then x_4 is sleeping.