**Motivations:**
- Produce a deterministic bridge from C3 local witnesses to universal-clause candidates (D/F) usable in later H4/H5 formalization.
**Root causes:**
- Local witnesses (Lift(B12)-scoped) were not exportable into a versioned, machine-checkable clause artefact.
**Correctifs:**
- Add deterministic extraction with minimal stable modulus lifting for D_exact/F and local encoding for D_brother dependencies.
- Add deterministic verifier checking arithmetic consistency, lifting stability, and brother↔mate relation.
**Evolutions:**
- Version universal clause artefacts (JSON/MD) under `docs/artefacts/collatz/universal_clauses/`.
- Document the feature and reproduction steps in `docs/features/`.
**Pages affectées:**
- applications/collatz/collatz_k_scripts/collatz_extract_universal_clauses.py
- applications/collatz/collatz_k_scripts/collatz_verify_universal_clauses.py
- docs/artefacts/collatz/universal_clauses/*
- docs/features/collatz_universal_clause_extraction_optionA.md
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