What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z_1, z_1 will not take a plane. For all z_1, if z_1 were a taxi driver, then z_1 is a soldier. For all z_1, z_1 is a soldier if and only if z_1 will take a plane. There is at least one z_1 for which if z_1 were a soldier, then z_1 is a taxi driver.
There is at least one z_1 for which z_1 is a soldier if and only if z_1 is a taxi driver. There is at least one z_1 for which z_1 is a taxi driver if and only if z_1 is a soldier. For all z_1, if z_1 were a soldier, then z_1 is taking a plane. For all z_1, if z_1 takes a plane, then z_1 is a soldier. For all z_1, z_1 is not a soldier.