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, x_2 will drink water or x_2 is a taxi driver. For all x_2, x_2 will not drink water or x_2 is a mechanic. There is at least one x_2 for which x_2 is not a taxi driver.
For all x_2, x_2 is a taxi driver or x_2 is a mechanic can be inferred via the universal resolution rule.