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_9, x_9 is an office clerk. For all x_9, x_9 will not play squash or x_9 will listen to a song. For all x_9, x_9 is a taxi driver or x_9 will play squash. For all x_9, x_9 is not a taxi driver.
For all x_9, x_9 will play squash can be inferred via the universal disjunctive syllogism rule.