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 sailor, then x_9 is a politician. For all x_9, if x_9 were an artist, then x_9 is a sailor. There is at least one x_9 for which if x_9 were a politician, then x_9 is not poor. For all x_9, x_9 is poor.
There is at least one x_9 for which x_9 is not a politician can be inferred via the existential modus tollens rule. For all x_9, if x_9 were an artist, then x_9 is a politician can be inferred via the universal transitivity rule.