P13-S21: the two precondition reasons the wire spec never named

PreconditionFailureReason 14 (AcousticRealizationPinned) and 15
(TranspositionOutOfRange) entered the vocabulary at Push 4a and reached this
document at neither place that owed them. The bounded enumeration ran 13 straight
to G3b's 16, and Push 4a's own history row recorded only OperationKind 30 while
saying nothing about the two reasons it appended in the same epoch. The Operation
Catalog documented both at its 0.8.0 and effect.rs has carried both throughout;
only the wire specification was silent.

This is P13-S20's specification-side twin, and it is why that decoder could stop
at 13 unchallenged: an implementer reading only the wire specification would have
built exactly that decoder and been right. No version bump and no new history
row -- this records an assignment normative since Push 4a rather than making one.

The regression test checks both sites, each bounded to its own longtable row,
because either alone is satisfiable by the wrong thing: the G3b row and the
enumeration both discuss PreconditionFailureReason at length, and an unbounded
search would go green the moment any row mentioned the names. Each half was
observed red alone while the other stayed green. The Push 4a row is located by a
version-free separator marker, per the file's standing rule against encoding a
document version number anywhere in it.

The epoch-12 evidence hash is e64a4b7, not this rung's parent. G3b landed across
six commits, and the chain records introducing commits -- the commit where
kind/tag 39 enters payload.rs and reasons 16-18 enter effect.rs -- exactly the
distinction the 2026-07-28 correction draws between 7df5ca1 and 55eff00 for G2a.
d58eee8 completes the rung and introduces no discriminant; both are named, with
their roles stated, in the plan and in the contract's pin 15.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QjsEnYhm1gPpf6ii2iFxFV

crates/epiphany-testkit/tests/binary_format_history.rs

@@ -36,6 +36,13 @@
 //! guard to its own Revision History row, closing the genesis ladder: the
 //! contract's own M71 deletes the G3b row, observes this guard fail, and
 //! restores it by hand.
+//!
+//! **P13-S21** extends the file past rung identity to one vocabulary gap of
+//! the same shape: `PreconditionFailureReason` 14 and 15 entered at Push 4a
+//! and reached this document at neither of the two places that owe them —
+//! not the bounded enumeration that assigns discriminants, and not Push 4a's
+//! own history row. See
+//! `precondition_failure_reasons_14_and_15_are_documented` below.
 
 use std::fs;
 use std::path::Path;
@@ -221,3 +228,87 @@ fn revision_history_g2b_row_states_what_g2b_did() {
          2 -> 3: {row_segment:?}"
     );
 }
+
+/// Slice one `longtable` row: from `marker` to the `\\` that terminates the
+/// row. Rows in this document carry no internal `\\`, so the first
+/// terminator after the marker ends that row and nothing else.
+fn row_segment<'a>(haystack: &'a str, marker: &str) -> &'a str {
+    let offsets = find_all(haystack, marker);
+    assert_eq!(
+        offsets.len(),
+        1,
+        "expected exactly one occurrence of the row marker {marker:?}, found {} \
+         (offsets {offsets:?})",
+        offsets.len()
+    );
+    let start = offsets[0];
+    let end = haystack[start..]
+        .find(r"\\")
+        .map(|relative| start + relative)
+        .unwrap_or(haystack.len());
+    &haystack[start..end]
+}
+
+/// `PreconditionFailureReason` 14 (`AcousticRealizationPinned`) and 15
+/// (`TranspositionOutOfRange`) entered the vocabulary at Push 4a — the
+/// Operation Catalog documented both at its own 0.8.0, and `effect.rs` has
+/// carried both ever since — but this document named neither anywhere, its
+/// bounded enumeration running 13 straight to G3b's 16. That is P13-S21, and
+/// it is why P13-S20's decoder could stop at 13 unchallenged: an implementer
+/// reading only the wire specification would have built exactly that decoder
+/// and been right.
+///
+/// **Both sites are checked, each bounded to its own row**, because either
+/// alone is satisfiable by the wrong thing. The G3b history row and the
+/// bounded enumeration both discuss `PreconditionFailureReason` at length, so
+/// an unbounded search for these names would go green the moment any row
+/// mentioned them — the same hole P13-S17 was filed over, one vocabulary
+/// down. No document version number appears here either; the Push 4a row is
+/// located by its version-free `--- Transpose algebra (Push~4a)` separator
+/// form, for the reason the module comment gives.
+///
+/// The enumeration is asserted as a **discriminant/name adjacency**, since it
+/// is the normative assignment and must be exact. The history row is asserted
+/// by name and discriminant presence within its own bounded segment: it is
+/// prose, its wording may legitimately be rewritten, and the bounding is what
+/// makes presence load-bearing there.
+#[test]
+fn precondition_failure_reasons_14_and_15_are_documented() {
+    let source = binary_format_source();
+    let normalized = normalize_whitespace(&source);
+
+    let enumeration = row_segment(
+        &normalized,
+        r"\texttt{Precondition\allowbreak FailureReason} &",
+    );
+    for pairing in [
+        r"\tablenums{14} AcousticRealizationPinned",
+        r"\tablenums{15} TranspositionOutOfRange",
+    ] {
+        assert!(
+            enumeration.contains(pairing),
+            "the bounded PreconditionFailureReason enumeration does not assign \
+             {pairing:?}; it is the normative discriminant assignment and the \
+             pairing must be exact: {enumeration:?}"
+        );
+    }
+
+    let push4a = row_segment(
+        revision_history_slice(&normalized),
+        "--- Transpose algebra (Push~4a)",
+    );
+    for owed in [
+        "AcousticRealizationPinned",
+        "TranspositionOutOfRange",
+        r"\tablenums{14}",
+        r"\tablenums{15}",
+    ] {
+        assert!(
+            push4a.contains(owed),
+            "Push 4a's own Revision History row does not record {owed:?}. Both \
+             reasons were appended in Push 4a's epoch alongside OperationKind 30, \
+             and a row that records only the kind leaves the append unattributable: \
+             {push4a:?}"
+        );
+    }
+}

spec/CONTRACT_GENESIS_G3B_MEASURE.md

@@ -623,7 +623,16 @@ events only**:
 |---|---|---|---|
 | 10 | G2b | `13c3d2f` | 2026-07-29 |
 | 11 | G3a | `6c5e69f` | 2026-07-29 |
-| 12 | G3b | this rung | — |
+| 12 | G3b | `e64a4b7` | 2026-07-30 |
+
+**Closed by the pre-push repair.** G3b landed across six commits, so its row
+needed the same distinction the 2026-07-28 correction draws for G2a: the
+introducing commit is **`e64a4b7`** (packet 1), where kind/tag 39 enters
+`ops/src/payload.rs` and reasons 16–18 enter `ops/src/effect.rs`. The four
+commits after it introduce no discriminant, and the rung *completes* at
+`d58eee8` (packet 3b, documentation). Recorded by the pre-push repair rather
+than by G3b itself, because a commit cannot cite its own hash and G3b closed
+the ladder — there was no later rung to fill it in.
 
 **G-minor and P13-S17 (`6170015`) do NOT belong in this chain** — G-minor
 built the epoch machinery and P13-S17 restored a document's history; neither

spec/PASS13_CANDIDATES.md

@@ -98,3 +98,4 @@ visible — a value with a wire form and no canonical carrier to reach it.)
 | P13-S18 | **Graph invariant 20's agreement and boundary-consistency checks are partial, and nothing yet closes the residue.** Genesis tranche G3b (`spec/CONTRACT_GENESIS_G3B_MEASURE.md` pin 7) makes invariant 20 ABSTAIN — emit no violation — wherever pin 6's comparable relation cannot order two measure starts or pin 6b's musical delta cannot be computed between them: cross-clock offsets (`Musical` vs `WallClock`), differing boundary selectors (`pos`/`edge`), and any `Measure` *end* anchor (unresolvable without the deferred tempo/measure-length machinery, `invariants.rs:400`ff). This is deliberate — base-ingested data may predate the rule, so flagging every incomputable case would make the invariant useless on real scores — but it is a real gap: a score whose measure/meter disagreement happens to fall in one of these incomputable shapes passes invariant 20 silently | `spec/CONTRACT_GENESIS_G3B_MEASURE.md` pin 7 (filed 2026-07-30 during the G3b contract's own drafting, ratified as deliberate abstention rather than a defect) | **open, deliberately.** Closing it needs the deferred P11-C5 resolved-position machinery: once a `Measure` end, or an event position on a wall-clock-placed region, can be placed on a common timeline, the comparable relation and the musical delta both widen and the abstention residue shrinks. No code change is owed by G3b itself |
 | P13-S19 | **`CreateMeasure`'s ordering and boundary-distance preconditions are vacuous for an instance's first measure, so pickup/anacrusis measures are unauthored by this rung.** Genesis tranche G3b (`spec/CONTRACT_GENESIS_G3B_MEASURE.md` pin 9) makes clauses 1 and 3 of `create_measure`'s append-only discipline vacuous when there is no predecessor measure, and invariant 20's boundary clause is symmetrically exempt for a first measure (core specification, invariant 20's doc comment) — a partial first measure MUST NOT be refused or flagged by either. This is a scoped deferral, not an oversight: a pickup measure's *own* internal consistency (its declared duration against its content) is a decomposition-sum question, not a measure-to-measure boundary question, and modelling it correctly needs a notion of "partial measure" this rung does not introduce | `spec/CONTRACT_GENESIS_G3B_MEASURE.md` pin 9 (filed 2026-07-30 during the G3b contract's own drafting) | **open, deliberately.** A pickup/anacrusis authoring story — whatever shape it takes — is later schema-fill work, sequenced after the genesis ladder closes |
 | P13-S20 | **`decode.rs`'s `precondition_reason` decoder stopped at discriminant 13, so `PreconditionFailureReason` 14 (`AcousticRealizationPinned`) and 15 (`TranspositionOutOfRange`), both live since Push 4a, encoded but could not decode.** A materialized effect carrying either reason failed canonical round-trip in production code, undetected because `epiphany-testkit`'s `precondition_failure_reason` generator (`generators.rs:417`, then `rng.below(14)`) never drew past 13 despite its doc comment claiming "every core and registered variant" | `spec/CONTRACT_GENESIS_G3B_MEASURE.md` §0 / touch-table row 12a (found 2026-07-30 during the G3b contract's own drafting, verified against the working tree: `decode.rs:205`ff ended at 13, `generators.rs:417` drew `below(14)`) | **RESOLVED in this rung** (genesis tranche G3b packet 1, `e64a4b7`). `decode.rs`'s `precondition_reason` now decodes discriminants 14 through 18 (the pre-existing 14/15 hole plus G3b's own 16–18), and `generators.rs`'s `precondition_failure_reason` now draws `below(19)` with arms for all of them — the generator's doc comment claim is true again, and the decode hole this rung found already latent in the tree, not introduced by it, is closed alongside G3b's own additions |
+| P13-S21 | **The wire specification never documented `PreconditionFailureReason` 14 and 15, so the decoder hole P13-S20 repaired had no normative text to be measured against.** `binary_format.tex`'s bounded reason table (`\sectionsc{Bounded Enumerations}`) ran `\tablenums{13}` straight to G3b's `\tablenums{16}`, and Push 4a's own Revision History row recorded only `OperationKind` `\tablenums{30}` (`TransposeInterval`) while saying nothing about the two reasons it appended in the same epoch. `AcousticRealizationPinned` and `TranspositionOutOfRange` appeared **nowhere** in the document, though the Operation Catalog documented both at 0.8.0 and `effect.rs` has carried both since Push 4a. This is P13-S20's specification-side twin: the same two variants, the same silence, and the reason a decoder that stopped at 13 could sit in the tree unchallenged — a conforming implementer reading only the wire specification would have built exactly that decoder and been right | Found 2026-07-30 while verifying genesis tranche G3b packet 3b (`d58eee8`), whose touch-table row 28 scoped the reason table to discriminants 16–18 only; the executing agent correctly declined to widen scope and reported the gap instead | **RESOLVED in this rung** (the G3b pre-push repair). The bounded table gains `\tablenums{14}` and `\tablenums{15}` with their refusal conditions, and Push 4a's Revision History row is amended to record both appends in its own epoch — no version bump and no new history row, because this documents an assignment that has been normative since Push 4a rather than making one. `binary_format_history.rs` gains a bounded regression test requiring both names in the reason table **and** in Push 4a's own row segment, so neither the G3b row's prose nor the Operation Catalog's coverage can satisfy it |

spec/PLAN_GMINOR_SCHEMA_MINOR.md

@@ -199,8 +199,14 @@ numbering spaces are unrelated and must not be cross-read.
 > the rung's one kind and its three `PreconditionFailureReason` appends
 > together, the Push 4a precedent (epoch 7 bundled kind 30 with reasons 14–15)
 > rather than a kind epoch and a reason epoch separately. The introducing
-> commit is this packet's own — the committing session owns `HEAD`, not this
+> commit is **`e64a4b7`** (2026-07-30), where kind/tag 39 enters
-> packet, so the hash is recorded once committed rather than invented here.
+> `ops/src/payload.rs` and reasons 16–18 enter `ops/src/effect.rs` — G3b landed
+> across six commits, and the four that follow packet 1 introduce no
+> discriminant, exactly the distinction the 2026-07-28 correction below draws
+> between `7df5ca1` and `55eff00`. The rung *completes* at **`d58eee8`**
+> (2026-07-30), the documentation half; the hash was filled in by the pre-push
+> repair that follows it, because a commit cannot cite itself and G3b closed
+> the ladder, leaving no later rung to do it.
 > The ladder stays monotonic (G3b follows G3a) and prefix-closed.
 
 **The ladder is complete against the audit** — every post-baseline variant in
@@ -215,8 +221,9 @@ introducing commits rather than assumed: M2c `a207077` (2026-06-25) → Push 3
 `92aaccf` (07-02) → Phase-3 `0316160` (07-02) → G-pass `e4edea6` (07-07) →
 repeat pair `9b5339f` (07-07) → Push 4a `2740a6c` (07-09) → G1 `3b09595`
 (07-24) → **G2a `7df5ca1`** (07-28) → **G2b `13c3d2f`** (07-29) → **G3a
-`6c5e69f`** (07-29) → **G3b** (this packet's own commit — the committing
+`6c5e69f`** (07-29) → **G3b `e64a4b7`** (07-30, the packet-1 commit where
-session owns `HEAD`, hash recorded there rather than invented here). The two
+kind/tag 39 and reasons 16–18 enter the vocabularies; the rung completes at
+`d58eee8`, which introduces no discriminant). The two
 events sharing 2026-07-07 are ordered correctly: the G-pass precedes the
 repeat revision. The two events sharing 2026-07-29 are ordered **by ancestry,
 not timestamp**: `13c3d2f` is an ancestor of `6c5e69f` (verified with

spec/binary_format.tex

@@ -1637,6 +1637,8 @@ trailing bytes are decode errors.
     \tablenums{11} TempoMapMalformed;
     \tablenums{12} SystemDerivedContentImmutable (Pass~12, P12-K3);
     \tablenums{13} RecreateContentMismatch (Pass~12, P12-K9);
+    \tablenums{14} AcousticRealizationPinned;
+    \tablenums{15} TranspositionOutOfRange (both Push~4a);
     \tablenums{16} MeasureMeterMismatch, \tablenums{17} MeasureOutOfOrder,
     \tablenums{18} MeasureOrderUnverifiable (genesis tranche G3b). \\
   \texttt{RepairRecord} &
@@ -3548,10 +3550,17 @@ only}: implementations need not agree on an error taxonomy.
   $\mathrm{seq}^{\Uparrow}$ notation (strictly increasing; a decoder
   \MUST{} reject a duplicate rather than normalize it) and marks
   \tablenums{9} (\texttt{Transpose}) frozen, its
-  $\mathrm{seq}^{\uparrow}$ being a multiset. No existing assignment
+  $\mathrm{seq}^{\uparrow}$ being a multiset. Appends two
-  changed. Semantics: Operation Catalog \sectionsc{TransposeInterval},
+  \texttt{PreconditionFailureReason} discriminants in the same epoch,
-  0.8.0; algebra: core Chapter~2, \sectionsc{Transposition and the
+  \tablenums{14} (\texttt{AcousticRealizationPinned}: a target whose
-  Interval Type}. \\
+  \texttt{AcousticRealization::AbsoluteHz} overrides the tuning system, so
+  moving its scale position would move the notehead without moving the
+  sound) and \tablenums{15} (\texttt{TranspositionOutOfRange}: an
+  \texttt{alteration} or \texttt{octave} driven past its \texttt{i8}
+  bound, where the frozen \tablenums{9} saturates and reports success).
+  No existing assignment changed. Semantics: Operation Catalog
+  \sectionsc{TransposeInterval}, 0.8.0; algebra: core Chapter~2,
+  \sectionsc{Transposition and the Interval Type}. \\
     \today & Chunk references & 0.8.0 --- Strict \texttt{CompressionAlgorithm}
   decode (Push~5, P3): \texttt{req:binfmt:compression-none-parameter} \MUST{}
   reject a non-zero parameter byte on the \texttt{None} discriminant. Ignoring