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 writes a letter, then y is rich. There is at least one y for which y will write a letter if and only if y is a musician. For all y, y will write a letter if and only if y is rich. For all y, y is not rich.
For all y, y will not write a letter. For all y, if y writes a letter, then y is rich. There is at least one y for which if y writes a letter, then y is a musician. For all y, if y were rich, then y is writing a letter. There is at least one y for which if y were a musician, then y is writing a letter. For all y, y will not write a letter.