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