# Experiment 60B.55 — Closure-normalization consolidation

**Date:** 2026-08-14
**Branch:** `feature/closure-selection-reconciliation-v0.41`

## Purpose

Consolidate and commit the already-proven closure-normalization fix after focused regression verification.

## Implementation state consolidated

The committed fix consists of four bounded changes only:

1. reverse resolution reconciliation
   - `updatedNodes.newStatus = "resolved"`
   - `-> resolvedUnknownNodeIds` automatically includes that existing unknown node

2. stale same-turn selectedQuestion clearing
   - if `selectedQuestion.nodeId` is resolved by the same proposal
   - `-> selectedQuestion = null` before strict validation

3. prompt clarification
   - `selectedQuestion` must remain unresolved after applying the proposal
   - if all consequential unknowns resolve, `selectedQuestion` must be null

4. repaired deterministic 60B.47 negative-closure regression structure

## Focused verification result

Command run:

```bash
npx vitest run \
  tests/graph/apply-proposal.test.js \
  tests/graph/prompt-builder.test.js \
  -t "60B.49|60B.52|60B.54|60B.43|60B.11|replaces downstream pricing|selectedQuestion|resolution"
```

Result:

- PASS — `38 passed | 151 skipped`

## Verified behaviours

### Exact negative closure regression

The exact 60B.47-shaped deterministic regression now passes through `applyValidatedProposal(...)` with:

- customer factor resolved
- decision resolved
- `resolvedUnknownNodeIds` / resulting `resolvedNodeIds` containing both IDs
- `activeUnknownNodeId = null`
- `selectedQuestion = null`

### Reconciliation invariants

Verified preserved:

- forward reconciliation
- already-consistent proposal unchanged
- no duplicate resolved IDs
- non-unknown nodes are not auto-added
- non-resolved statuses are not auto-added

### Fallback preservation

Verified preserved:

- stale same-turn resolved selectedQuestion clears cleanly
- another genuine unresolved candidate still becomes the fallback target

### Existing behavioural regressions preserved

Verified preserved:

- 60B.43 terminal post-mutation closure regression
- 60B.11 preferred-target behaviour
- pricing prerequisite-first regression
- prompt-builder selectedQuestion rule regression

## What is now guaranteed

The deterministic engine now normalizes same-turn closure structure coherently before strict validation:

- resolved existing unknowns are represented in both status and `resolvedUnknownNodeIds`
- a same-turn resolved `selectedQuestion` cannot survive as stale structure
- strict validator semantics remain intact

## What remains unproven

The exact live negative-outcome closure still needs one bounded rerun after this deterministic fix to confirm the same end state through the live model-driven path.