Consider the following premises. For all x_6, x_6 will not make tea. There is at least one x_6 for which if x_6 were a scientist, then x_6 is making tea. For all x_6, x_6 is a scientist if and only if x_6 will make tea. Can we infer the following from them? For all x_6, x_6 is a scientist.
 From the fact that for all x_6, x_6 is a scientist if and only if x_6 will make tea we can infer that for all x_6, if x_6 makes tea, then x_6 is a scientist. From the fact that for all x_6, if x_6 makes tea, then x_6 is a scientist, and that there is at least one x_6 for which if x_6 were a scientist, then x_6 is making tea we can infer that there is at least one x_6 for which x_6 will make tea if and only if x_6 is a scientist. Finally, from the fact that there is at least one x_6 for which x_6 will make tea if and only if x_6 is a scientist, and that for all x_6, x_6 will not make tea we can infer that there is at least one x_6 for which x_6 is not a scientist, which contradicts that For all x_6, x_6 is a scientist. Therefore, the answer is no.