Sanaa's slow shelf

Claim (verbatim)

Sanaa's slow shelf. This connects library ecology with the age structure of surviving copies. In high-churn metropolitan book markets, old copies were superseded, sold off, and scrapped: replacement, not catastrophe, is the great killer of early exemplars. Yemen's Zaydi libraries sat in a low-churn ecology, thin markets, continuous institutions, no fashion cycle in scripts and bindings, so the same work should survive there in systematically older copies than in metropolitan collections. Not because Yemen copied earlier, but because it discarded later: the periphery preserves antiquity by failing to refresh its stock, and the copy-age gap measures the metropolitan replacement rate.

Prediction clause (verbatim)

For works extant both in digitized Yemeni collections and in Middle Eastern or European collections, the oldest Yemeni copy predates the oldest non-Yemeni copy in more than 50% of shared works, and the median age advantage of the Yemeni exemplar exceeds 75 years. Primary clause: the majority clause, the Yemeni copy older in more than half of shared works; the verdict follows it. Secondary: the 75-year median gap.

Kill-dataset (verbatim)

Kill: vHMML's digitized Yemeni manuscript metadata (the Zaydi manuscript digitization projects) matched work-by-work against dated copies in FIHRIST.

Novelty / leakage triage

provisional — model-triaged, shepherd review pending

A provisional first pass authored by the model (Opus), not yet confirmed by the shepherd. It carries the same dated-search requirements as an authoritative verdict but is excluded from every headline figure and cannot underwrite a prediction until a shepherd confirms it. Provisional reading: Adjacent (closely related prior work exists).

The direction is documented: because Yemen is 'relatively remote from the central lands of Islam, it has preserved many extremely rare sources, including some of the earliest extant' texts (the rationale of the Zaydi Manuscript Tradition and Yemeni digitization projects), i.e. a low-churn periphery preserving old material. Not located: the item's sharper, comparative claim and its mechanism -- that for works extant BOTH in Yemen and elsewhere the oldest Yemeni copy is older in >50% of shared works with a median age advantage >75 years, NOT because Yemen copied earlier but because it discarded later (the periphery measuring the metropolitan replacement rate) -- matched work-by-work between vHMML Yemeni metadata and FIHRIST. Remoteness-preserves-antiquity is documented; the copy-age-differential-as-replacement-rate measurement is unrun.

• HMML Zaydi Manuscript Tradition (ZMT) / Yemeni Manuscript Digitization Initiative -- Yemen's remoteness preserving rare and early copies — Low-churn periphery preservation; the direction the item sharpens
• vHMML digitized Yemeni manuscript metadata matched work-by-work against dated copies in FIHRIST — The kill dataset for the shared-work copy-age comparison

Predictions

No prediction registered yet.