What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, y is an office clerk if and only if y will write a letter. For all y, if y writes a letter, then y is an office clerk.
For all y, if y were an office clerk, then y is writing a letter. For all y, if y writes a letter, then y is an office clerk.