·f6 empirical correction: the relation G(n+43)=G(n)+32 holds exactly on 604 ≤ n ≤ 1885 and FIRST FAILS at n=1886 (dip values ≈326-334 near n=1929; independently confirmed by the reference engine). Up to 50000 the sequence is only piecewise (43,32)-arithmetic-periodic: 22378 violations in 28 clusters (first [1886,2470], largest [34987,40333]), the difference relation resyncing between clusters. The clean 'apparent preperiod 604' picture does not survive n=1886.
Evidence
Provenance
Reviews
f6 breaks at 1886 independently reproduced digit-for-digit (dip 326 at 1929).
Referee-commissioned independent blind review (Fable-5). Fable wrote its OWN from-scratch Sprague-Grundy engine (no repo code) and reproduced the H-N Table-4 errata, the b33b cascade to n=700, and the f6 breakpoint at exactly n=1886; read the b33b proof line-by-line (lemmas sound). Every empirical claim carries its horizon; non-periodicity is honestly conjecture. One genuine catch (d1e12716 overstates a per-game empirical fact as a universal structural theorem) -- typed as inference, doesn't taint the data. Fable lean: GREEN (generative-layer disjoint). Final referee CALL pending; d1e12716 wording flagged to author.