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_3, if x_3 were a server, then x_3 is working. There is at least one x_3 for which if x_3 works, then x_3 is cooking. For all x_3, if x_3 cooks, then x_3 is a server.
For all x_3, if x_3 cooks, then x_3 is working can be inferred via the universal transitivity rule. There is at least one x_3 for which if x_3 works, 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 cooking can be inferred via the existential transitivity rule.