Consider the following premises. For all x_7, if x_7 writes a letter, then x_7 is not a lawyer. For all x_7, x_7 is a lawyer and x_7 is a nurse. For all x_7, x_7 will write a letter or x_7 is a sailor. Can we infer the following from them? There is at least one x_7 for which x_7 is not a sailor.
 From the fact that for all x_7, x_7 is a lawyer and x_7 is a nurse we can infer that for all x_7, x_7 is a lawyer. From the fact that for all x_7, if x_7 writes a letter, then x_7 is not a lawyer, and that for all x_7, x_7 is a lawyer we can infer that for all x_7, x_7 will not write a letter. Finally, from the fact that for all x_7, x_7 will write a letter or x_7 is a sailor, and that for all x_7, x_7 will not write a letter we can infer that for all x_7, x_7 is a sailor, which contradicts that There is at least one x_7 for which x_7 is not a sailor. Therefore, the answer is no.