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