What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, if y were a cashier, then y is cooking. There is at least one y for which y is a doctor if and only if y is a cashier. For all y, y is a cashier if and only if y is a doctor. For all y, y will not cook.
For all y, y is not a cashier. For all y, if y were a cashier, then y is a doctor. There is at least one y for which if y were a doctor, then y is a cashier. For all y, if y were a doctor, then y is a cashier. There is at least one y for which if y were a cashier, then y is a doctor.