What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all y, if y were an artist, then y is a poet. For all y, if y were a poet, then y is an artist. For all y, y is an artist or y is not a poet.
For all y, if y were a poet, then y is an artist can be inferred via the universal rewriting rule. For all y, y is an artist if and only if y is a poet can be inferred via the universal biconditional introduction rule. For all y, y is a poet if and only if y is an artist can be inferred via the universal biconditional introduction rule.