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Levi Neuwirth 986b90aef3 P13-S6: the tuning constructions, drafted -- and why sourcing was not enough
`req:tuning:builtin-tuning-catalog` MUST-resolves 20 tuning identifiers while
specifying only the six `tet-*`. Ruling B keeps all 20 and pins them by
**construction** rather than by cents table, because published sources agree on
constructions and differ mainly in rounding. This lands the draft of the other
14 as a **non-normative** artifact for review; nothing enters `core_spec.tex`
until the four open ratifications are decided.

Drafting rather than editing was deliberate, and it earned its keep. An agent
writing Werckmeister III from memory into a normative document is the
`NOTEHEAD_ANCHORS` failure exactly: hand-written, authoritative-looking,
unverifiable in-tree, and load-bearing.

**The first draft was well-sourced and wrong.** Ten entries, ten live citations,
zero recalled, zero unknown -- and three of them could not exist. A twelve-fifth
circle must absorb exactly one Pythagorean comma (23.4600 c). Checked:

  kirnberger-ii   2 x 1/2 syntonic, "remaining ten pure"  -> 21.5063 c
  kirnberger-iii  4 x 1/4 syntonic, "remaining eight pure" -> 21.5063 c

Both short by 1.9537 c -- exactly one schisma, the signature of a dropped
schisma-tempered fifth. The draft said of the first, in terms, "This closes the
circle." It does not. And `werckmeister-iii` carried the syntonic-vs-Pythagorean
comma forward as a "genuinely ambiguous" hedge into its summary table, when
closure settles it: only the Pythagorean reading closes, and a well temperament
that does not close is not one.

The supporting reasoning had been *correct* -- the derivation that C-E, G-B and
D-F# come out pure is right. The error was inferring from it that every
remaining fifth is pure. Making those thirds just does not discharge the full
comma. That is precisely the failure a citation count cannot detect and an
invariant catches in one line.

**Corrected and re-verified by recomputation, not by re-reading.** All six
circulating temperaments now close to exactly 23.4600 c; all four
non-circulating residues reproduce independently (`pythagorean` 678.495 c;
meantone 1/4, 1/5, 1/6 wolves 737.637 / 725.809 / 717.923 c). The schisma fifth
is sourced at F#-Db, and Kirnberger III's four fifths are now a direct quotation
rather than a reconstruction.

**The best result is a disagreement.** Recomputing Kirnberger II's thirds from
its own chain, the agent found its new source's prose claims four pure thirds
where the construction yields three -- F-A comes out at 397.067 c, not 386.314.
It reported the conflict instead of deferring to the source or dropping it.
Independently confirmed to the cent.

The count is still 10 verified / 0 recalled / 0 unknown, but `verified` now
means sourced **and** invariant-checked. The number did not move; its meaning
did. A stable metric hiding a changed reality is this session's recurring lesson
in another costume.

`CONTRACT_P13S6_TEMPERAMENTS.md` gains a permanent section, "Check the
arithmetic, not just the source", stating the general principle first so it
transfers: a citation proves the source said it, not that it is right, that you
read it correctly, or that you transcribed it completely. Five obligations --
closure; closure as a decision procedure for vague sources; non-circulating
temperaments must *not* close, with the wolf computed; twelve fifths each
exactly once; recompute every derived claim and treat disagreement as a finding.
Plus the guard that matters most: never adjust a construction to make the
arithmetic work and present it as sourced -- that manufactures a temperament
nobody published. An unresolved entry is the correct output.

Still open, surfaced not decided: the three `ji-static-5limit-*` scales and
`ji-adaptive-5limit`'s algorithm, the latter recommended to follow
`req:pitch:spelling-algorithm`'s versioned-identifier pattern.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-22 11:50:06 -04:00
.github/workflows Push 4: Binary Format companion, F1 benches, subquadratic reduction order 2026-07-02 19:02:07 -04:00
crates P13-S5 and P13-S6: the two inherited claims were both true 2026-07-22 09:03:39 -04:00
spec P13-S6: the tuning constructions, drafted -- and why sourcing was not enough 2026-07-22 11:50:06 -04:00
.gitignore Schema major 1 Phase F: ratify engrave I8/I9/I10 + process trail 2026-07-06 17:40:38 -04:00
CONFORMANCE.md Pass 12 G-pass: ratify the full batch (28 rows) — spec tranche 2026-07-07 10:23:30 -04:00
Cargo.lock Text Projection: whole-document conformance, and a corpus with teeth 2026-07-21 15:44:25 -04:00
Cargo.toml Text Projection: the document layer, and the equation closes 2026-07-21 15:05:28 -04:00