Consider the following premises. For all x_4, if x_4 were a nurse, then x_4 is playing squash. For all x_4, if x_4 plays squash, then x_4 is playing a game. For all x_4, if x_4 plays a game, then x_4 is a nurse. Can we infer the following from them? If Richard plays squash, then Richard is a nurse.
 From the fact that for all x_4, if x_4 plays squash, then x_4 is playing a game, and that for all x_4, if x_4 plays a game, then x_4 is a nurse we can infer that for all x_4, if x_4 plays squash, then x_4 is a nurse. From the fact that for all x_4, if x_4 plays squash, then x_4 is a nurse, and that for all x_4, if x_4 were a nurse, then x_4 is playing squash we can infer that for all x_4, x_4 will play squash if and only if x_4 is a nurse. From the fact that for all x_4, x_4 will play squash if and only if x_4 is a nurse we can infer that Richard is playing squash if and only if Richard is a nurse. Finally, from the fact that Richard is playing squash if and only if Richard is a nurse we can infer that if Richard plays squash, then Richard is a nurse. Therefore, the answer is yes.