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: There is at least one x_1 for which if x_1 were a janitor, then x_1 is not drinking water. For all x_1, if x_1 plays tennis, then x_1 is drinking water. For all x_1, x_1 will play tennis.
For all x_1, x_1 will drink water can be inferred via the universal modus ponens rule.