Consider the following premises. For all x_8, if x_8 were a server, then x_8 is an office clerk. There is at least one x_8 for which x_8 is curious if and only if x_8 is a server. For all x_8, x_8 is an office clerk if and only if x_8 is a mechanic. For all x_8, x_8 is not a mechanic. Can we infer the following from them? If we can, name the inference rule being used: For all x_8, x_8 is curious.
 From the fact that for all x_8, x_8 is an office clerk if and only if x_8 is a mechanic, and that for all x_8, x_8 is not a mechanic we can infer that for all x_8, x_8 is not an office clerk via universal biconditional elimination. From the fact that for all x_8, if x_8 were a server, then x_8 is an office clerk, and that for all x_8, x_8 is not an office clerk we can infer that for all x_8, x_8 is not a server via universal modus tollens. Finally, from the fact that there is at least one x_8 for which x_8 is curious if and only if x_8 is a server, and that for all x_8, x_8 is not a server we can infer that there is at least one x_8 for which x_8 is not curious via existential biconditional elimination, which contradicts that For all x_8, x_8 is curious. Therefore, the answer is no.