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: There is at least one x_3 for which if x_3 sleeps, then x_3 is listening to a song. For all x_3, if x_3 listens to a song, then x_3 is a server. For all x_3, if x_3 were a server, then x_3 is sleeping.
For all x_3, if x_3 listens to a song, then x_3 is sleeping can be inferred via the universal transitivity rule. There is at least one x_3 for which if x_3 sleeps, then x_3 is a server can be inferred via the existential transitivity rule. There is at least one x_3 for which if x_3 were a server, then x_3 is listening to a song can be inferred via the existential transitivity rule.