P13-S19 is filed as a deferral. It is closer to a live defect, and the tree
already contains the proof: m35_boundary_flags_wrong_distance places a first
measure at offset 0 and its successor half a whole note later, under a signature
whose measure_duration is a whole, and asserts invariant 20 fires. That is a
pickup, and the test has been labelled "wrong distance" since packet 2.
create_measure applies the same rule as a refusal. So authoring a pickup does
not merely leave it unmodelled -- it makes the rest of the instance unauthorable.
The rung corrects seven surfaces, three of them normative, one of them
outright false: ops/DECISIONS.md says all three CreateMeasure clauses are
vacuous for a first measure, and the agreement clause has no predecessor
dependency at all. It observes the reducer refusal rather than citing it, files
the Chapter 3 splitter deferral as its own candidate, and introduces no
partial-measure notion -- that is a semantic rung and pin 9 stops this one at
its edge.
Three over-readings committed while drafting are recorded inside the contract
rather than smoothed away, because text that is locally true and globally
misleading is the rung's own subject. It claimed a pickup is "neither refused
nor flagged" (the agreement clause runs on a first measure); it claimed that
again more weakly after the first fix (referential preconditions and invariant
10 still apply); and it listed core/DECISIONS.md as an understated surface by
matching "never flagged" without reading the qualifier that makes it correct.
That file is now explicitly out of bounds, with the reason, so a later reader
comparing it against the corrected ops entry does not "fix" the one site that
already draws the distinction.
The absence gate replaces a grep that could not fail. Two of its seven phrases
straddle a newline, so a line-oriented search would have returned nothing before
the correction as well as after; the gate normalizes whitespace, and all seven
anchors were confirmed present at 339269b so it fails today and can pass only
once the work lands.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QjsEnYhm1gPpf6ii2iFxFV
Levi Neuwirth
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