 (UT) is an elementary logical fact that has been long recognized (see, e.g., Glymour 1980a, 36). In purely formal terms, just positing \(k = h \rightarrow e\) will do for a proof. To appreciate how (UT) can spark any philosophical interest, one has to combine it with some insightful remarks first put forward by Pierre Duhem (1906) and then famously revived by Quine (1951) in a more radical style. (Indeed, (UT) essentially amounts to the “entailment version” of “Quinean underdetermination” in Laudan 1990, 274.)