What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y_3, y_3 will work if and only if y_3 is a carpenter. There is at least one y_3 for which y_3 will work if and only if y_3 is a carpenter.
For all y_3, if y_3 works, then y_3 is a carpenter. There is at least one y_3 for which if y_3 works, then y_3 is a carpenter. For all y_3, if y_3 were a carpenter, then y_3 is working. There is at least one y_3 for which if y_3 were a carpenter, then y_3 is working.