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 y_2, y_2 will play tennis if and only if y_2 is a bartender. There is at least one y_2 for which y_2 is a bartender or y_2 will not play tennis.
There is at least one y_2 for which if y_2 plays tennis, then y_2 is a bartender can be inferred via the existential rewriting rule. For all y_2, if y_2 plays tennis, then y_2 is a bartender can be inferred via the universal biconditional elimination rule. For all y_2, if y_2 were a bartender, then y_2 is playing tennis can be inferred via the universal biconditional elimination rule.