What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Charles is not playing squash or Barbara is sleeping. For all x_9, x_9 is a bartender or x_9 will listen to a song. Patricia is not listening to a song or it is raining. Patricia is not a bartender or Charles is playing squash.
Nothing can be inferred from these premises.