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: For all x_4, if x_4 were a server, then x_4 is making tea. For all x_4, x_4 is rich. For all x_4, if x_4 were rich, then x_4 is a server. For all x_4, x_4 will work.
For all x_4, x_4 is a server can be inferred via the universal modus ponens rule. For all x_4, if x_4 were rich, then x_4 is making tea can be inferred via the universal transitivity rule. For all x_4, x_4 is rich and x_4 will work can be inferred via the universal conjunction rule. For all x_4, x_4 will work and x_4 is rich can be inferred via the universal conjunction rule.