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, if y were a police officer, then y is a soldier. There is at least one y for which y will sleep if and only if y is a police officer. For all y, if y were a soldier, then y is sleeping.
For all y, if y were a police officer, then y is sleeping can be inferred via the universal transitivity rule. There is at least one y for which if y sleeps, then y is a police officer can be inferred via the existential biconditional elimination rule. There is at least one y for which if y were a police officer, then y is sleeping can be inferred via the existential biconditional elimination rule.