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, if y_3 were a sailor, then y_3 is a writer. For all y_3, y_3 is a sailor if and only if y_3 is a writer.
For all y_3, if y_3 were a sailor, then y_3 is a writer. For all y_3, if y_3 were a writer, then y_3 is a sailor.