Consider the following premises. There is at least one x_7 for which x_7 will play squash or x_7 is an electrician. For all x_7, if x_7 plays a game, then x_7 is taking a plane. For all x_7, if x_7 were an electrician, then x_7 is playing a game. For all x_7, x_7 will play squash if and only if x_7 will take a plane. Can we infer the following from them? For all x_7, x_7 will not take a plane.
 From the fact that for all x_7, x_7 will play squash if and only if x_7 will take a plane we can infer that for all x_7, if x_7 plays squash, then x_7 is taking a plane. From the fact that for all x_7, if x_7 were an electrician, then x_7 is playing a game, and that for all x_7, if x_7 plays a game, then x_7 is taking a plane we can infer that for all x_7, if x_7 were an electrician, then x_7 is taking a plane. Finally, from the fact that for all x_7, if x_7 plays squash, then x_7 is taking a plane, that for all x_7, if x_7 were an electrician, then x_7 is taking a plane, and that there is at least one x_7 for which x_7 will play squash or x_7 is an electrician we can infer that there is at least one x_7 for which x_7 will take a plane, which contradicts that For all x_7, x_7 will not take a plane. Therefore, the answer is no.