What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x, x will write a letter if and only if x is a writer. There is at least one x for which x is a writer or x will not write a letter.
There is at least one x for which if x writes a letter, then x is a writer. For all x, if x writes a letter, then x is a writer. For all x, if x were a writer, then x is writing a letter.