What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_4, x_4 is a poet or x_4 is a carpenter. For all x_4, if x_4 were a carpenter, then x_4 is sad. For all x_4, x_4 is sad if and only if x_4 is a poet.
For all x_4, if x_4 were sad, then x_4 is a poet. For all x_4, if x_4 were a poet, then x_4 is sad.