Consider the following premises. For all x_3, x_3 is happy. For all x_3, x_3 is an artist and x_3 is a writer. Can we infer the following from them? There is at least one x_3 for which either x_3 is happy or x_3 is an artist are not true.
 From the fact that for all x_3, x_3 is an artist and x_3 is a writer we can infer that for all x_3, x_3 is an artist. Finally, from the fact that for all x_3, x_3 is happy, and that for all x_3, x_3 is an artist we can infer that for all x_3, x_3 is happy and x_3 is an artist, which contradicts that There is at least one x_3 for which either x_3 is happy or x_3 is an artist are not true. Therefore, the answer is no.