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 an office clerk and x_9 will read a book. There is at least one x_9 for which x_9 is not a poet. For all x_9, x_9 is a poet or x_9 is a writer.
There is at least one x_9 for which x_9 is a writer can be inferred via the existential disjunctive syllogism rule. For all x_9, x_9 is an office clerk can be inferred via the universal simplification rule. For all x_9, x_9 will read a book can be inferred via the universal simplification rule.