Ratified 2026-07-24, resolving Ruling B blocker (i). Pass-12 K8 is reversed:
every mutable field of Score becomes operation-authored, and a document is
Score::empty(identity) plus its envelope log. The instrument, staff, staff
instance, voice, event chain is authorable end to end.
The decision removes machinery rather than adding it. Every alternative kept
genesis outside the operation set and then had to pay for that: a new chunk
role, a manifest field, an immutability rule, and a merge or fail-closed rule
for a canonical payload with no CRDT semantics. Genesis state is edited —
instruments get added, page geometry changes, temperaments are chosen — and
each alternative made those edits single-writer, unmergeable, or impossible.
Concurrency is a first-order product commitment, so the exception was not
worth institutionalising in the format.
Scope is nine surfaces over two templates already proven in reduce.rs: three
LWW settings setters on the SetMetadata pattern (canvas.layout_defaults,
tuning_context, spelling_precedence) and six entity mint families on the
CreateStaff pattern (instruments, staff_groups, parts, analysis_layers, views,
and StaffInstance.measures), each with graph-aware referential preconditions.
Delete and modify coverage is left to the tranche contract rather than assumed,
since CreateStaff itself ships today with no DeleteStaff.
Measures are ruled authored rather than derived. TimeAnchor::Measure carries a
measure id that cross-cutting structures anchor to, so deriving measures from
the metric grid would make their identity a function of the meter and every
time-signature change would orphan the anchors pointing into them. The cost
accepted is that measure/meter consistency becomes an authoring obligation
backed by a graph invariant.
Three constraints are written in rather than left implicit. Pruning may not be
implemented until the canonical base carries graph values: a prune installs a
MaterializedState base whose effects are outcomes, not payloads, so nothing
rebuilds the score afterward — silent and total, and free to prohibit now
because no prune exists to break. The from-empty path must reduce through
new_onto with an empty Score rather than base-free, because the base-free mode
skips graph-aware preconditions by design and would silently lose referential
enforcement from the first operation. And the OperationEnvelopeBlock accept-set
raise 2 to 3 is spent once, so the new kinds land as one batch — this is a
different major from Push 4b's schema major 3, the Score and Snapshot role wire
that tranche 3b-i froze, and there is no free ride between them.
The analysis is corrected in place rather than rewritten, so the evidence the
ruling rests on stays readable. Two amendments: Measure is a ninth uncovered
surface the original table missed by scoring canvas.regions at container
granularity, and identity is promoted from a stated question to a blocking one
— IdentityContext is replica-scoped yet lives on Score and is encoded, so under
from-empty reduction two replicas with an identical log produce Scores
differing in an encoded field while the music is identical. That disposition
blocks specification of the tranche and is deliberately not ruled here.
Execution belongs to the Push-4b-class coordinated track; the editor track
consumes it. T1b's lease, save, and single-writer machinery does not depend on
the tranche landing and may be contracted in parallel.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Two documents, both prerequisites rather than implementations.
CONTRACT_EDITOR_T4PRE_IR.md charters the layout-IR readiness tranche Ruling A
names as its prerequisite: per-system primitive ownership (W1), the shared
typed glyph-asset seam (W2, contracted but not dispatched), and the text-run
primitive decision (W3, an analysis packet). Its central finding reframes the
work — casting-off already computes the ownership partition and the fold into
ResolvedLayoutIR drops it on the floor, so W1 is "stop discarding it", exact
rather than heuristic. Eight design pins, six named mutations, and a
byte-neutrality gate that keeps the tranche compatible with the Push-4b
freeze.
The contract survived a source-level review that found one real defect: the
blast radius audited ResolvedLayoutIR literals but not ResolvedSystem's, and
pin 1 adds a field to both — editor-core's two-system hit-test fixture is a
full literal with no spread, so the packet could not compile the workspace
without it. Amended, along with the SystemId claim (no *production*
constructor; testkit's random cache generator has one), the stub solver's
total provenance aliasing, and the stroke-continuation citation.
ANALYSIS_GENESIS_PERSISTENCE.md is the field-by-field Score table Ruling B
blocker (i) requires before it can be resolved. It decides nothing; it
establishes what is true. Eight of Score's twenty fields have no operation
that can produce them — canvas.layout_defaults (the printed page geometry),
instruments, staff_groups, parts, tuning_context, spelling_precedence,
analysis_layers, views, plus identity — and decomposition_attachments can be
pruned but never authored. Each is reachable only through a base the reducer
is handed, and pruning is licensed to replace that base with a
MaterializedState carrying none of them.
Three findings follow: the genesis root is unreachable from an empty base
(CreateStaff preconditions a live instrument; nothing creates an instrument),
the canonical base cannot carry what the base-only fields hold, and there is
no canonical wire path from bundle bytes to a Score at all. They are one
problem from three sides — the format has no representation for graph state
that no operation authors.
Four dispositions are laid out with costs: a canonical genesis block, closing
the op-coverage gap, promoting the canonical base to carry graph values, or
scope-limiting T1b. The recommendation is the last now and the third as the
destination, because only that one makes pruning safe for every field rather
than for an enumerated list, and T4b needs the same checkpoint mechanism
regardless.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Levi Neuwirth