What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_1, x_1 is a sailor if and only if x_1 is a taxi driver. There is at least one x_1 for which if x_1 were a taxi driver, then x_1 is a lawyer. For all x_1, x_1 is not a lawyer.
There is at least one x_1 for which x_1 is not a taxi driver. For all x_1, if x_1 were a sailor, then x_1 is a taxi driver. For all x_1, if x_1 were a taxi driver, then x_1 is a sailor.