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 y for which y will not take a plane. For all y, if y were poor, then y is a server. For all y, y will take a plane or y is not a server. For all y, if y takes a plane, then y is poor.
For all y, if y takes a plane, then y is a server can be inferred via the universal transitivity rule. For all y, if y were a server, then y is taking a plane can be inferred via the universal rewriting rule.