Consider the following premises. For all x_5, if x_5 takes a plane, then x_5 is a musician. For all x_5, if x_5 were an artist, then x_5 is taking a plane. For all x_5, x_5 is a poet if and only if x_5 is a musician. For all x_5, x_5 is an artist or x_5 is a poet. Can we infer the following from them? There is at least one x_5 for which x_5 is not a musician.
 From the fact that for all x_5, if x_5 were an artist, then x_5 is taking a plane, and that for all x_5, if x_5 takes a plane, then x_5 is a musician we can infer that for all x_5, if x_5 were an artist, then x_5 is a musician. From the fact that for all x_5, x_5 is a poet if and only if x_5 is a musician we can infer that for all x_5, if x_5 were a poet, then x_5 is a musician. Finally, from the fact that for all x_5, if x_5 were an artist, then x_5 is a musician, that for all x_5, if x_5 were a poet, then x_5 is a musician, and that for all x_5, x_5 is an artist or x_5 is a poet we can infer that for all x_5, x_5 is a musician, which contradicts that There is at least one x_5 for which x_5 is not a musician. Therefore, the answer is no.