Consider the following premises. For all z_3, if z_3 were a sailor, then z_3 is drinking water. For all z_3, z_3 is a sailor if and only if z_3 will drink water. Can we infer the following from them? For all z_3, if z_3 were a sailor, then z_3 is drinking water.
That is one of the premises. Therefore, the answer is yes.