# Phase 173.2 Summary: LibRPA QSGW Replay And Three-Lane Convergence Closure

**Status:** Done
**Date:** 2026-04-14
**Axis:** Axis 4 (human evidence) + Axis 5 (agent-facing roadmap clarity)

## What was done

Phase `173.2` closed milestone `v1.99` at the phase level.

### Replay closure

- replayed the bounded `LibRPA QSGW` positive-L2 proof mechanically
- wrote one short replay runbook for the bounded first-principles lane

### Three-lane convergence closure

- wrote one explicit note that the user-requested three directions now each
  have a bounded positive baseline:
  - pure formal theory: `v1.97`
  - toy model numerical + derivation: `v1.98`
  - large codebase / first-principles / algorithm development: `v1.99`

## Acceptance criteria

- [x] One replayable acceptance lane proves the bounded positive `LibRPA QSGW` route mechanically
- [x] One runbook explains how to replay that positive-L2 proof end to end
- [x] One durable note makes the three-lane convergence baseline explicit
- [x] Milestone `v1.99` is left ready for lifecycle handling

## Evidence

| Artifact | Location | Purpose |
|----------|----------|---------|
| `replay-librpa-qsgw-positive-l2.json` | `phases/173.2-librpa-qsgw-replay-and-three-lane-convergence-closure/evidence/` | Raw replay of the bounded positive `LibRPA QSGW` authoritative-L2 landing |
| `pytest-librpa-qsgw-positive-l2.txt` | `phases/173.2-librpa-qsgw-replay-and-three-lane-convergence-closure/evidence/` | Targeted replay receipt for the bounded positive-L2 wrapper |
| `three-lane-convergence.md` | `phases/173.2-librpa-qsgw-replay-and-three-lane-convergence-closure/evidence/` | Explicit note that all three requested research directions now have bounded positive baselines |
| `receipt.md` | `phases/173.2-librpa-qsgw-replay-and-three-lane-convergence-closure/evidence/` | Human-readable replay receipt |

## Outcome

With Phase `173.2`, all three phases of milestone `v1.99` are complete:

- Phase `173`: bounded `LibRPA QSGW` target and trust contract ✅
- Phase `173.1`: positive `LibRPA QSGW` promotion to authoritative `L2` ✅
- Phase `173.2`: replay closure and three-lane convergence note ✅

The milestone is now ready for lifecycle handling: audit, complete, and
archive.
