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_15, x_15 is happy or x_15 will play squash. For all x_15, if x_15 plays squash, then x_15 is listening to a song. For all x_15, x_15 is not happy.
For all x_15, x_15 will play squash can be inferred via the universal disjunctive syllogism rule.