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_13, if x_13 were a scientist, then x_13 is a sailor. For all x_13, x_13 will play tennis or x_13 is a scientist. For all x_13, if x_13 plays tennis, then x_13 is a sailor. For all x_13, x_13 will drive a car. There is at least one x_13 for which if x_13 drives a car, then x_13 is a bartender.
There is at least one x_13 for which x_13 is a bartender can be inferred via the existential modus ponens rule. For all x_13, x_13 is a sailor can be inferred via the universal disjunction elimination rule.