Consider the following premises. There is at least one x_7 for which if x_7 were a scientist, then x_7 is a sailor. For all x_7, x_7 is curious and x_7 is an artist. For all x_7, if x_7 were a sailor, then x_7 is not curious. Can we infer the following from them? If we can, name the inference rule being used: For all x_7, x_7 is a scientist.
 From the fact that for all x_7, x_7 is curious and x_7 is an artist we can infer that for all x_7, x_7 is curious via universal simplification. From the fact that for all x_7, if x_7 were a sailor, then x_7 is not curious, and that for all x_7, x_7 is curious we can infer that for all x_7, x_7 is not a sailor via universal modus tollens. Finally, from the fact that there is at least one x_7 for which if x_7 were a scientist, then x_7 is a sailor, and that for all x_7, x_7 is not a sailor we can infer that there is at least one x_7 for which x_7 is not a scientist via existential modus tollens, which contradicts that For all x_7, x_7 is a scientist. Therefore, the answer is no.