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_2, if x_2 were a carpenter, then x_2 is not a scientist. There is at least one x_2 for which x_2 is a carpenter or x_2 is a bartender. For all x_2, x_2 is a scientist.
For all x_2, x_2 is not a carpenter can be inferred via the universal modus tollens rule.