Per fox: apply the conservative max_envelope B1 model by changing the
v1 calculator's default — NOT by forking a v2. CALCULATOR_VERSION stays
"t3-bound-v1-bottou-refinement" (the descriptor names the unchanged B3
term); b1_model is echoed in the output AND the inputs dict so KAT
replays are unambiguous about which model produced a row.
Calculator (bench/scripts/t3_bound_calculator.py):
- New b1_model kwarg + --b1-model CLI flag, choices:
max_envelope (default) max(fraction_channels, aggregate_bias)
fraction_channels g · W · log₂(1 + G/σ)
aggregate_bias W · log₂(1 + g·G/σ)
effective_control_v1 g · W · log₂(1 + g·G/σ) (old non-worst-case)
- Default is now max_envelope — genuinely upper-bounding across both
interpretations of g (dav1d review §3 closure blocker, RESOLVED).
- Every output reports all three concrete B1 variants
(B1_fraction_channels / B1_aggregate_bias / B1_effective_control_v1),
b1_selected, and both SNR readings (snr_grad = g·G/σ,
snr_per_channel = G/σ) regardless of which b1_model was requested.
- model_assumptions[] now carries f"B1_model_{b1_model}".
- inputs echo now includes c_b1/c_b2/c_b3/b1_model (replay-complete).
- Invalid b1_model rejected with a ValueError naming the field.
- Baseline I_window: 625.8716 (effective_control_v1) → 6183.0154
(max_envelope: B1=aggregate_bias 5849.63 dominates fraction_channels
1729.72), certification_status NOT_CERTIFIED_BY_BOUND at W=10000.
KAT fixture (bench/fixtures/t3-bound/known-answer-tests.jsonl):
- Regenerated 2026-05-11 — 12 entries: the 8 §7-derived configs under
the new max_envelope default, a g=0 edge case, plus explicit-mode
pins for effective_control_v1 / fraction_channels / aggregate_bias.
- Each entry carries b1_model, expected_b1_selected,
expected_b1_{fraction_channels,aggregate_bias,effective_control_v1},
expected_snr_per_channel, expected_certification_status.
Tests (tests/test_t3_bound_calculator.py, 75 → 83):
- test_t3_bound_known_answer_tests no longer skips (fixture active);
pins b1_model, b1_selected, certification_status + numbers, tolerates
optional new fields on older fixtures.
- New: test_b1_max_envelope_exact_formula, test_invalid_b1_model_rejected,
test_cli_b1_model_flag (effective_control_v1 / fraction_channels /
aggregate_bias). test_b1_exact_formula renamed
test_b1_effective_control_v1_exact_formula and now passes the explicit
model. Updated baseline / below-256 / CLI tests for the new numbers.
Doc (docs/soft-hash-channel-t3-bound.md):
- Header + §0 + §3.1 + §6 + §7 (worked examples) + §8 (operator
guidance W-solving) + §10 (closure blockers RESOLVED) + §10.1 +
§11 (calculator schema) + §12 all updated for the max_envelope
default. §8: target-256 W drops from ~4196 to ~415 steps under the
conservative model — the ~10× cost of not assuming which g-reading
holds; operators who can measure effective-control applies can use
--b1-model effective_control_v1 for the looser W (a calibration
claim they must justify, not a default).
Status (#000036 ticket + TICKETS.md): both prior dav1d closure
blockers cleared (B1 worst-case model + active KAT fixture); remaining
= fox's final close-or-iterate call.
AUTOCOUNT markers bumped 75 → 83. Full suite: 2288 passed, 28 skipped.
russell@unturf.com
1d1a942d57