The Textbook Comparison — the ledger against the formula it descends from, scored both ways

The deposit has spent a month measuring its own errors. This paper measures the alternative's. On the same 2,938 nuclides, by the same least squares, the deposit's four-knob ledger is put against the semi-empirical mass formula (SEMF) it descends from — twice, because there is a flashy comparison and a fair one, and the flashy one is fenced here before anyone can misuse it. The fair sentence, which is the strong one: the ledger matches the fully refitted textbook formula — 2.42 against 2.53 MeV mean absolute error — with one fewer fitted constant, its Coulomb coefficient derived from alpha rather than fitted, and a win on the light end where the alpha lives. [earned — with the fence of §2] The paper then records two closures that the day's questions earned: the Fermi-gas half of the asymmetry coefficient (52% of comes free, naming the sharpest knob-removal target the ledger has), and the external-environment question, closed by arithmetic and by measurement at once. This record holds one paper on its own and is refreshed every couple of months. The complete deposit, 10.5281/zenodo.21788037, holds every paper with its code and data and is updated first; for the newest version of this paper, go there.