Consider the following premises. For all z, if z were an artist, then z is making tea. For all z, if z were a carpenter, then z is making tea. For all z, z is a carpenter. Can we infer the following from them? If we can, name the inference rule being used: For all z, z will make tea.
 From the fact that for all z, z is a carpenter we can infer that for all z, z is a carpenter or z is an artist via universal addition. Finally, from the fact that for all z, if z were a carpenter, then z is making tea, that for all z, if z were an artist, then z is making tea, and that for all z, z is a carpenter or z is an artist we can infer that for all z, z will make tea via universal disjunction elimination. Therefore, the answer is yes.