Promote ADR-0025 from Draft (design note) to Accepted with the
architectural home decision reversed: rotor admissibility lives at
the same generation/propagation seam as ADR-0024's destination
check — in a sibling-but-separate module
`generate/rotor_admissibility.py` — NOT in `algebra/versor.py` or
`field/propagate.py`.
Algebra rejected because admissibility is a pack-semantic test, not
a closure invariant; placing it there couples algebra to pack state
and creates structural temptation toward grade-projection repair
(CLAUDE.md §Normalization Rules forbids). field/propagate rejected
as a forbidden normalization site even when framed as precondition
guard. The clean answer is generation-side, in its own file:
endpoint admissibility (token-side, blade) and rotor admissibility
(rotor-side, frame) compose at the same seam while remaining
conceptually separable.
New module generate/rotor_admissibility.py:
RotorVerdict — admit/reject + score + region_label + reason
check_rotor_admissibility(region, *, field_current, rotor)
-> RotorVerdict
Pure semantic check:
F' = versor_apply(V, F_current)
score = cga_inner(F', region.frame_versor)
admit iff score > 0 (basic positivity in frame half-space)
No state mutation, no closure enforcement (algebra's job).
region.frame_versor is None → trivial admit (back-compat).
RefusalReason extended:
INNER_LOOP_EXHAUSTION — destination-side (ADR-0024 / ADR-0026)
ROTOR_REJECTION — rotor-side (this ADR)
The two reasons let the trace name the axis that ran out without a
parallel exception type. InnerLoopExhaustion(ValueError) hierarchy
unchanged; back-compat preserved.
Wiring in generate/stream.py:
threshold mode per-candidate rotor check after destination admit;
reject → log rotor score, retry next candidate;
exhaustion routes reason to ROTOR_REJECTION iff
any rotor rejection occurred in the step
margin mode rotor check on the top-ranked admissible candidate;
reject → immediate InnerLoopExhaustion(
reason=ROTOR_REJECTION) carrying the destination
ranking + the rejected rotor's score
Phase 4 keeps positivity (score > 0), not margin, on the rotor side.
No cross-case calibration evidence to inform a rotor-margin constant
yet; promoting to ranked-with-margin awaits Phase 5 diversified-
families evidence. Destination-side margin (ADR-0026) is unchanged.
Teaching boundary closed at Stance A — strictly hygiene-only.
Rotor rejections are deterministic geometric outcomes, not reviewed
teaching examples. CLAUDE.md §Teaching Safety forbids parallel
correction paths; entangling rotor rejection with reviewed teaching
would create one. Confirmed in ADR-0025 §"Teaching boundary".
Acceptance evidence (tests/test_rotor_admissibility.py, 11 passing):
No-frame back-compat — frame_versor=None tokens identical to
Phase 3 baseline
Admit when aligned — frame_versor=seed direction admits
seed→destination rotor
Refuse with named axis — orthogonal frame raises
InnerLoopExhaustion(reason=ROTOR_REJECTION); threshold mode
also routes reason correctly
versor_condition < 1e-6 preserved on admitted rotors
Deterministic replay — 5 reruns identical for both admitted and
refused turns
Suite results:
full: 1048 passed, 2 skipped (+11 new rotor tests)
docs/runtime_contracts.md updated with "Rotor admissibility contract"
subsection documenting the seam, the algorithm, and the refusal
taxonomy.
Architectural invariants preserved:
no new code in algebra/versor.py, field/propagate.py, vault/store.py
no approximate recall, no cosine similarity, no HNSW/ANN
no hot-path repair; check is pure typed-verdict
InnerLoopExhaustion(ValueError) hierarchy unchanged
Phase 2 — Corpus observation runner (inner_loop_runner.py):
- Four-condition matrix: boundary_only / null_control / inner_loop_t0 / inner_loop_tpos.
- Added `inner_loop_force_admit` to generate() — exercises the inner-loop
code path but force-breaks on first candidate. Eval-only null control:
isolates rejection as the causal factor for any pass-rate delta.
- Metrics: pass_rate, mean_rejection_count_per_turn,
non_empty_rejected_attempts_rate, exhaustion_rate (gated at 5%),
mean_admissibility_checks_per_turn, mean/p95 added_latency_ms,
trace_hash_stability across 5 reruns per case.
- Finding on v1+dev: causal_attribution_valid=True, code_path_residual=0.0,
but exhaustion_rate=0.33 at t=0 — chain outer-product blade is
geometrically blind to the active pack.
- Tests (tests/test_inner_loop_phase2.py, 5 pass): pin
causal-attribution and live-corpus trace-hash stability invariants.
Phase 3 — Mechanism-isolation v2 corpus (5 cases, v2_runner.py):
- Synthetic adversarial cases with controlled geometry — each case
specifies seed_token, admissible_tokens, relation_blade_token, and
admissibility_threshold. Field state is constructed directly from
the seed token versor, not via priming.
- For every case: boundary-only selects the forbidden decoy and
inner-loop selects the expected endpoint with the forbidden token
appearing in rejected_attempts.
- Result: mechanism_isolated=true on 5/5. boundary_decoy_rate=1.0,
rejection_traced_rate=1.0. Inner-loop rejection is demonstrably
doing causal semantic work on real packs.
- Tests (tests/test_inner_loop_phase3.py, 8 pass): GATE on
mechanism_isolated.
Phase 4 — Threshold characterization (threshold_characterization.py):
- Distribution mapping per-case AND globally on v1+dev, v2, combined.
- Per-threshold sweep over [-1.0, -0.5, 0.0, 0.1, 0.25, 0.5, 1.0].
- Finding: per-case geometry separates cleanly (correct_min > incorrect_max
on every v2 case), BUT no global static threshold passes the
separation_quality >= 0.8 gate. Blade norms vary ~10x across cases.
- Static thresholds (global, relation-typed, or constant frame-derived)
are geometrically insufficient. Per-case-normalized thresholds
(e.g. fraction of blade self-score) are the recommended next step.
- v1 chain-token outer-product cases all skipped — the corpus's chain
tokens (alpha, beta, gamma, delta) are not grounded in the active
pack. Load-bearing finding for ADR-0025 region construction.
- Tests (tests/test_inner_loop_phase4.py, 5 pass): pin the finding
diagnostically (not gated).
Phase 5 — ADR-0025 design note (draft):
- No code changes proposed. Scopes three architectural questions:
(1) home (algebra/versor.py vs field/propagate.py vs generate/) —
preliminary stance: algebra/versor.py.
(2) threshold scheme (blade-normalized fraction recommended over
static; learned/adaptive rejected for determinism).
(3) teaching-loop boundary — Stance A confirmed: rejections are
runtime hygiene only, no entanglement with teaching/*.
- Decisions to be closed before Draft → Accepted.
Phase 1 acceptance criteria from previous commit (7fccf36) carry
forward: wired, deterministic-when-wired, legacy hash preserved.
Suite: 1014 passed, 0 failed, 2 skipped.
Shay