Consider the following premises. For all x, x will play squash or x will play tennis. For all x, x will not play squash. For all x, if x plays tennis, then x is a musician. There is at least one x for which x is a sailor. Can we infer the following from them? For all x, either x is a sailor or x is a musician are not true.
 From the fact that for all x, x will play squash or x will play tennis, and that for all x, x will not play squash we can infer that for all x, x will play tennis. From the fact that for all x, if x plays tennis, then x is a musician, and that for all x, x will play tennis we can infer that for all x, x is a musician. Finally, from the fact that there is at least one x for which x is a sailor, and that for all x, x is a musician we can infer that some sailors are musicians, which contradicts that For all x, either x is a sailor or x is a musician are not true. Therefore, the answer is no.