Consider the following premises. For all x_10, if x_10 sleeps, then x_10 is an electrician. For all x_10, if x_10 goes running, then x_10 is sad. For all x_10, x_10 is sad if and only if x_10 is an electrician. For all x_10, x_10 will not play a game or x_10 will go running. There is at least one x_10 for which x_10 will play a game or x_10 will sleep. Can we infer the following from them? For all x_10, x_10 is not sad.
 From the fact that there is at least one x_10 for which x_10 will play a game or x_10 will sleep, and that for all x_10, x_10 will not play a game or x_10 will go running we can infer that there is at least one x_10 for which x_10 will sleep or x_10 will go running. From the fact that for all x_10, x_10 is sad if and only if x_10 is an electrician we can infer that for all x_10, if x_10 were an electrician, then x_10 is sad. From the fact that for all x_10, if x_10 sleeps, then x_10 is an electrician, and that for all x_10, if x_10 were an electrician, then x_10 is sad we can infer that for all x_10, if x_10 sleeps, then x_10 is sad. Finally, from the fact that for all x_10, if x_10 sleeps, then x_10 is sad, that for all x_10, if x_10 goes running, then x_10 is sad, and that there is at least one x_10 for which x_10 will sleep or x_10 will go running we can infer that there is at least one x_10 for which x_10 is sad, which contradicts that For all x_10, x_10 is not sad. Therefore, the answer is no.