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 will climb a mountain if and only if y is a poet. For all y, y is a poet or y will not write a letter. There is at least one y for which if y climbs a mountain, then y is a poet.
For all y, if y writes a letter, then y is a poet. For all y, if y climbs a mountain, then y is a poet. For all y, if y were a poet, then y is climbing a mountain.