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_10 for which x_10 is a taxi driver. For all x_10, x_10 is a soldier or x_10 is a mechanic. For all x_10, x_10 is not a soldier or x_10 will play tennis. For all x_10, if x_10 were a mechanic, then x_10 is not a taxi driver.
There is at least one x_10 for which x_10 is not a mechanic can be inferred via the existential modus tollens rule. For all x_10, x_10 is a mechanic or x_10 will play tennis can be inferred via the universal resolution rule.