What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_10, x_10 is a lawyer if and only if x_10 is a nurse. For all x_10, x_10 is a lawyer or x_10 is a poet. There is at least one x_10 for which x_10 is not a poet. For all x_10, x_10 is not a nurse.
Since the premises are contradictory, we can infer anything from them.