Consider the following premises. Joseph is not an artist. For all x_8, if x_8 were an artist, then x_8 is an office clerk. For all x_8, if x_8 were an office clerk, then x_8 is an artist. Joseph is an office clerk if and only if Susan is taking a plane. Can we infer the following from them? Susan is taking a plane.
 From the fact that for all x_8, if x_8 were an artist, then x_8 is an office clerk, and that for all x_8, if x_8 were an office clerk, then x_8 is an artist we can infer that for all x_8, x_8 is an artist if and only if x_8 is an office clerk. From the fact that for all x_8, x_8 is an artist if and only if x_8 is an office clerk we can infer that Joseph is an artist if and only if Joseph is an office clerk. From the fact that Joseph is an artist if and only if Joseph is an office clerk, and that Joseph is not an artist we can infer that Joseph is not an office clerk. Finally, from the fact that Joseph is an office clerk if and only if Susan is taking a plane, and that Joseph is not an office clerk we can infer that Susan is not taking a plane, which contradicts that Susan is taking a plane. Therefore, the answer is no.