What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? James is taking a plane if and only if Susan is making tea. For all z, if z were a sailor, then z is making tea. For all z, if z makes tea, then z is a sailor. James is not taking a plane.
If James takes a plane, then Susan is making tea. If Susan makes tea, then James is taking a plane. Susan is not making tea. For all z, z is a sailor if and only if z will make tea. For all z, z will make tea if and only if z is a sailor.