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 cashier, then y is working. There is at least one y for which y will work if and only if y is a cashier.
There is at least one y for which if y works, then y is a cashier can be inferred via the existential biconditional elimination rule. There is at least one y for which if y were a cashier, then y is working can be inferred via the existential biconditional elimination rule.