# LIB2-065 — The loaded first row determines its displayed Vud magnitude

- class: CLAIM · review_state: PUBLISHED · house_tier: not yet assigned
- labels as printed: math_status NOT_PRINTED · attachment NOT_PRINTED · scorecard tier word Loaded (PDF p.58)
- basis: {"pdf_sha256_prefix": "b64ddcd9e16a6dcd", "release": "Rev33.1_S369"}

## Statement

The retained first-row relation |Vud| = √(1 − |Vus|² − |Vub|²) gives the displayed value 0.97429 and inherits the first-row loading.

## Caution

The unitarity-derived value inherits the route choice and is not an independent confirmation of that choice.

## Primary source

Paper 3, §2, First-row unitarity readout, PDF p.49: "first-row unitarity gives q |Vud | = 1 − |Vus |2 − |Vub |2 ≈ 0.97429. (3)"

## Machine

- url: /library-v2/LIB2-065/
- content_sha256: 4c771bc9d9eaccfac0ad2d9d2d9a102a41d70b2971f2851016cf2a25a657c8f4
- candidate_ids: C2-008

## Freshness

- BUILD_STAMP S371a · 2026-09-26T22:53Z · master 01d1a5873ede42f5 · cut 9dcc6ce9a8ee3e02
- Declared volatile fields (R36): BUILD_STAMP