Consider the following premises. For all x_13, if x_13 were excited, then x_13 is fast. For all x_13, if x_13 plays squash, then x_13 is excited. For all x_13, x_13 is excited if and only if x_13 will take a plane. For all x_13, if x_13 were fast, then x_13 is excited. For all x_13, x_13 will take a plane or x_13 will play squash. Can we infer the following from them? For all x_13, x_13 is fast.
 From the fact that for all x_13, x_13 is excited if and only if x_13 will take a plane we can infer that for all x_13, if x_13 takes a plane, then x_13 is excited. From the fact that for all x_13, if x_13 takes a plane, then x_13 is excited, that for all x_13, if x_13 plays squash, then x_13 is excited, and that for all x_13, x_13 will take a plane or x_13 will play squash we can infer that for all x_13, x_13 is excited. From the fact that for all x_13, if x_13 were fast, then x_13 is excited, and that for all x_13, if x_13 were excited, then x_13 is fast we can infer that for all x_13, x_13 is fast if and only if x_13 is excited. From the fact that for all x_13, x_13 is fast if and only if x_13 is excited we can infer that for all x_13, if x_13 were excited, then x_13 is fast. Finally, from the fact that for all x_13, if x_13 were excited, then x_13 is fast, and that for all x_13, x_13 is excited we can infer that for all x_13, x_13 is fast. Therefore, the answer is yes.