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, x_9 is a writer and x_9 is a sailor. For all x_9, x_9 is not rich. For all x_9, x_9 is rich or x_9 is a poet.
For all x_9, x_9 is a poet can be inferred via the universal disjunctive syllogism rule. For all x_9, x_9 is a writer can be inferred via the universal simplification rule. For all x_9, x_9 is a sailor can be inferred via the universal simplification rule.