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_3, y_3 will sleep if and only if y_3 is poor. For all y_3, y_3 will play squash or y_3 is poor. For all y_3, if y_3 plays squash, then y_3 is sleeping.
For all y_3, if y_3 sleeps, then y_3 is poor can be inferred via the universal biconditional elimination rule. For all y_3, if y_3 were poor, then y_3 is sleeping can be inferred via the universal biconditional elimination rule.