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, x_4 is a server if and only if x_4 will sleep. For all x_4, x_4 is a server if and only if x_4 will take a plane. For all x_4, x_4 will not sleep.
For all x_4, if x_4 were a server, then x_4 is sleeping. For all x_4, if x_4 were a server, then x_4 is taking a plane. For all x_4, if x_4 sleeps, then x_4 is a server. For all x_4, if x_4 takes a plane, then x_4 is a server. For all x_4, x_4 is not a server.