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_6, x_6 is a bartender. For all x_6, x_6 is a poet or x_6 is an artist. For all x_6, if x_6 were a poet, then x_6 is not a bartender. There is at least one x_6 for which x_6 is a nurse.
For all x_6, x_6 is not a poet can be inferred via the universal modus tollens rule. Some nurses are bartenders can be inferred via the existential conjunction rule. Some bartenders are nurses can be inferred via the existential conjunction rule.