wrote Waverly,
was Scotch" is always true.
These three propositions, translated into ordinary language, state:
(1) at least one person wrote Waverly;
(2) at most one person wrote Waverly;
(3) whoever wrote Waverly was Scotch.
All these three are implied by "the author of Waverly was Scotch." Conversely, the three together (but no two of them) imply that the author of Waverly was Scotch. Hence the three together may be taken as defining what is meant by the proposition "the author of Waverly was Scotch."
We may somewhat simplify these three propositions. The first and second together are equivalent to: "There is a term
