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_10, x_10 is a writer or x_10 is rich. It is not raining. If it rains, then Thomas is a writer. If Thomas were a writer, then it is raining.
Thomas is not a writer can be inferred via the modus tollens rule.