Consider the following premises. For all x_11, if x_11 were a nurse, then x_11 is sleeping. For all x_11, if x_11 were a cashier, then x_11 is happy. For all x_11, x_11 is a nurse or x_11 will not sleep. There is at least one x_11 for which x_11 is a cashier or x_11 will sleep. For all x_11, if x_11 were happy, then x_11 is a nurse. Can we infer the following from them? For all x_11, x_11 is not a nurse.
 From the fact that for all x_11, x_11 is a nurse or x_11 will not sleep we can infer that for all x_11, if x_11 sleeps, then x_11 is a nurse. From the fact that for all x_11, if x_11 were a cashier, then x_11 is happy, and that for all x_11, if x_11 were happy, then x_11 is a nurse we can infer that for all x_11, if x_11 were a cashier, then x_11 is a nurse. From the fact that for all x_11, if x_11 sleeps, then x_11 is a nurse, and that for all x_11, if x_11 were a nurse, then x_11 is sleeping we can infer that for all x_11, x_11 will sleep if and only if x_11 is a nurse. From the fact that for all x_11, x_11 will sleep if and only if x_11 is a nurse we can infer that for all x_11, if x_11 sleeps, then x_11 is a nurse. Finally, from the fact that for all x_11, if x_11 were a cashier, then x_11 is a nurse, that for all x_11, if x_11 sleeps, then x_11 is a nurse, and that there is at least one x_11 for which x_11 is a cashier or x_11 will sleep we can infer that there is at least one x_11 for which x_11 is a nurse, which contradicts that For all x_11, x_11 is not a nurse. Therefore, the answer is no.