  In the context of a scientific claim, ‘X by-means-of-the-fact-that or in-the-respect-that X is Y is F’ maintains that ‘Y is F’ is a theorem, where Y is the most universal or appropriate subject for F, and that X is F in virtue of the fact that X is Y. For example, Figure ABC qua triangle has internal angles equal to two right angles, but qua right triangle has sides AB2 + BC2 = AB2.