# P3-S22.4 — FEATURE / LABEL CONTRACT VALIDATION

```text
Date       : 2026-08-26
Session    : P3-S22.4 — CORRECTED POPULATION + FEATURE/LABEL CONTRACT VALIDATION
Status     : COMPLETE (contract validation only)
Result     : FEATURE CONTRACT UNCHANGED ; LABEL CONTRACT UNCHANGED
Policy     : docs/CODE_VERIFICATION_AND_SILENT_BUG_POLICY_v1.md
Owner      : chiki2bum2 (authoritative repo)
Namespace  : ml/p3/p3_s224_corrected_population_validation/
```

## Scope

This companion report documents the FEATURE and LABEL contract-facing parts
(C, D, E, F, G, H, I, K) of P3-S22.4 applied to the corrected 707-setup
population. It proves the corrected population satisfies the FROZEN feature
schema (12 causal features) and the P3-S16 label contract v1 unchanged, and
that row values differ only as an expected consequence of the corrected M30
semantics.

## A. Feature contract validation (frozen 12-feature schema)

```text
Feature version : P3-S18_feature_snapshot_v1
Schema columns  : direction, h4_gate, m30_gate, sweep_age_bars,
                  choch_age_bars, choch_latency_bars, zone_type_code,
                  zone_age_bars, zone_width_atr, price_in_zone_offset,
                  dist_to_zone_center_atr, atr_at_entry
Count / names / order : identical to frozen
dtypes / missing / finite : numeric / 0 / all finite
as-of availability       : all closed-bar-as-of at entry
namespace separation     : identity_ / feature_ / label_ separated

feature_sha16 (corrected population) : ff07b2bf74af4b3c
feature_sha16 (frozen P3-S18/20)     : 0414e401522ea4e2
schema_sha16 (schema-only)           : ae64573dc6d5cba0
```

**Contract finding:** the feature SCHEMA is unchanged. The population-derived
`feature_sha16` differs because the row population changed (707 vs 686).
This is an expected population consequence of the corrected UTC-clock M30
construction, NOT a feature-contract change. No feature was added, removed,
reordered, renamed, or redefined.

## B. Feature semantic availability

Every one of the 12 features is generated from closed-bar information
available at or before ENTRY (creation-bar close). A future-value injection
audit mutated each feature individually; the semantic audit detected the
mutation in 12/12 cases.

## C. Structural redundancy (documented, unchanged)

```text
h4_gate == m30_gate == direction  (every row)              : True
dist_to_zone_center_atr == price_in_zone_offset - 0.5      : True
choch_latency_bars == sweep_age_bars - choch_age_bars      : True
zone_type_code constant  (OB population)                   : True
```

These are by-construction / affine identities of the verified canonical
chain. Documented and validated; NO feature is removed or altered.

## D. Label contract validation (P3-S16 v1, unchanged)

Contract parameters (frozen, not modified): entry = creation-bar close,
K_TP = 1.5 ATR, K_SL = 0.75 ATR, H = 16, first-hit TP-before-SL, same-bar
ambiguity rule.

Corrected population accounting:

```text
total corrected population   : 707
corrected leads             : 610
corrected follow-ons        : 97
total == leads + follow-ons  : True
lead class accounting : WIN 175 / LOSS 404 / UNRESOLVED 25 / AMBIGUOUS 6
lead class sum == 610        : True
```

No outcome forced; UNRESOLVED = true censoring; AMBIGUOUS = same-bar conflict
never forced to WIN/LOSS.

## E. Leakage / silent-bug audit (dataset-generation controls)

The CODE_VERIFICATION_AND_SLENT_BUG_POLICY_v1 dataset-generation controls
were exercised via an 8-mutation battery (future feature, future label, row
shift, timestamp shift, duplicate row, deleted row, shuffled row, M30 gate
substitution). Detection result: 8/8.

## F. Sample-size (corrected binary-fit)

```text
corrected binary-fit N : 579 (WIN 175 / LOSS 404)   -- see sample_size_readiness.json
frozen P3-S20 binary-fit N : 571 (167 WIN / 404 LOSS)
```

Statistical statement only. ML sufficiency is decided in the authorized ML
experiment auth step, not by this validation.

## G. Integrity statement

```text
Feature contract modified : NO
Label contract modified   : NO
TP/SL/horizon modified    : NO
Frozen P3-S18/P3-S20 artifacts modified : NO
Any ML trained / evaluated / calibrated : NO
```

*End of P3-S22.4 feature/label contract validation.*