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_9, if x_9 were a server, then x_9 is a soldier. For all x_9, x_9 is a sailor or x_9 is a poet. For all x_9, x_9 is not a sailor. For all x_9, x_9 is a server.
For all x_9, x_9 is a soldier can be inferred via the universal modus ponens rule. For all x_9, x_9 is a poet can be inferred via the universal disjunctive syllogism rule.