Resolution: Killed
Caveats: (1) Register/genre confound: Ur III is overwhelmingly administrative while OB adds literary, lexical, scholarly and epistolary registers; this was explicitly tested by refitting on Administrative-only subsets, and the reversal persists (Ur III-admin 0.346 vs OB-admin 0.433), so the rise is not merely a register artifact, though the OB-admin subset is much smaller (4.5k texts). (2) A genuine deep-time signal exists: the oldest strata (Uruk IV/III 0.611/0.554, ED IIIa 0.552) have the highest betas and beta declines across the 3rd millennium, consistent with a slowly closing sign inventory -- but this decline is diffuse and is not located at the OB school-standardization transition the conjecture named. (3) Plausible reinterpretation: Ur III's anomalously low beta (a 3,711-sign closed bureaucratic monoculture) suggests the Ur III state's own accounting standardization was the sign-economizing episode, with OB scribal culture re-expanding sign variety; the 'standardization compresses inventory' intuition has some life, but attached to the wrong transition and the wrong direction relative to the registered prediction. (4) Clause-wording gap: the KILLED clause literally reads 'linear or exponent-stable across the transition,' and the exponent is neither -- it changes significantly in the reverse direction. This verdict resolves the gap by reading the kill clause, per the registrant's own disclosure pinning resolution to the standardization-collapse claim, as 'no discontinuous drop': a significant rise refutes the pinned drop at least as decisively as stability would, and campaign precedent (breadth-india-009, timur's-fingerprint, coins-014/PELLA) treats a reversed primary pinned comparison as a kill. (5) The sublinearity limb (Heaps' law, R^2 0.977-0.991 in all 12 strata) is fully met but carries no support weight: the registrant explicitly disclosed the prior that type-token curves are near-universally sublinear and pinned the test to the collapse clause. (6) Coverage limit: the CDLI ATF dump leaves later 1st-millennium strata largely catalogue-only, so the transition test rests on the well-covered 3rd-2nd millennium strata; the decisive Ur III/OB comparison is, however, among the best-covered in the corpus.
OPEN prediction (in-house resolution impossible — CDLI transliterations confirmed not held): the cuneiform sign inventory grows with corpus size by Heaps' law (V = K*N^beta, 0 < beta < 1), and beta drops discontinuously across the Old Babylonian school-standardization transition.
Resolution criteria — the registered fine print
Resolution criteria: Resolvable against public sign-level corpora (CDLI/ORACC transliterations) by computing type-token growth curves within period strata. SUPPORTED if the growth fits a sublinear power law (R^2 >= 0.95 on log-log) in every period stratum AND the fitted beta in post-standardization Old Babylonian strata is lower than in pre-standardization strata by more than the bootstrap 95% interval width. KILLED if vocabulary growth is linear or exponent-stable across the standardization transition.
Known-priors disclosure — what the registrant already knew
Known priors disclosure: No sign-level data in-house (Phase-A finding: catalogue metadata only). The registrant holds the general prior that type-token curves are near-universally sublinear — hence the kill condition is pinned to the sharper standardization-collapse clause, not to sublinearity alone.
Method and dataset — how it was measured
Sign-level tokenizer: signs split on -,.,+,: within words; determinatives {..} counted as signs; number notation n(SIGN) -> SIGN; compounds |..| as one sign; damage/uncertainty markup stripped; x/n/... dropped. Heaps' law V = K*N^beta fitted by OLS on the log-log type-accumulation curve averaged over 50 random text orderings, with bootstrap 95% CIs on beta from 300 text-resamples per stratum and a paired bootstrap for the Ur III vs Old Babylonian difference. A genre control refit beta on Administrative-only subsets of both transition strata to test the register confound. The compute was run outcome-blind (claude-sonnet script) and independently reproduced by the orchestrator with a separate tokenizer and vectorization; all four decisive point-betas matched within 0.01. Verdict reasoning: The registered SUPPORTED verdict requires both limbs; limb 1 (sublinear Heaps fit, R^2 >= 0.95 everywhere) is met, but limb 2 fails decisively: post-standardization Old Babylonian beta (0.471) is not lower than the pre-standardization strata -- it sits above five of eight pre-strata, and against its immediate predecessor Ur III (0.348) the paired-bootstrap difference of -0.123 (95% CI [-0.160, -0.078]) excludes zero in the wrong direction, a significant rise where a significant drop was predicted. The registrant's own priors disclosure pinned resolution to the sharper standardization-collapse clause precisely because sublinearity alone was conceded in advance, so meeting limb 1 cannot rescue the conjecture. A directional reversal is strictly stronger disconfirmation of the pinned drop than exponent-stability; reading it as outside the kill clause would reward the conjecture for being more wrong. The genre-controlled check shows the reversal is not a register artifact, and the blind, independently reproduced compute removes analyst-degrees-of-freedom concerns. The predicted discontinuous beta drop at the Old Babylonian school-standardization transition is contradicted by a significant rise; the conjecture is killed on its pinned clause.
Dataset: CDLI bulk ATF transliteration dump (github.com/cdli-gh/data, CC BY 4.0), 135,185 tokenizable texts joined to CDLI catalogue period metadata, yielding 12 cuneiform/proto-cuneiform period strata with >=1000 tokenizable texts each, spanning Uruk IV through Neo-Assyrian. The decisive transition comparison rests on the heavily covered Ur III (76.8k texts, 5.63M sign tokens) and Old Babylonian (2.16M sign tokens) strata.
computed 2026-07-20