# Fork/gather research evidence — 2026-09-06

These are historical research inputs, not approved specifications or production
code. The current contract is the
[draft fork/gather spec](../../../superpowers/specs/2026-09-06-fork-gather-design.md).
The [ADR](../../../adr/0006-explicit-fork-and-topology-driven-gather.md) records
the architectural direction. Both remain proposed.

## Provenance

Eight files were copied, not moved, from `random shit/research-chatgpt/`.
Every copy was checked against its original with SHA-256. The redundant ZIP,
older citation-less exports, and other unrelated research were not imported.

| Archived file under `imported/` | Original relative path |
| --- | --- |
| `round-2-report.md` | `deep-research-report060926 copy 3.md` |
| `round-2-citations.md` | `deep-research-report060926 copy 2.md` |
| `audit-1.md` | `research-audit060926.md` |
| `audit-2.md` | `research-audit060926-002.md` |

The remaining four files retain their original basenames and were copied from
the `research-audit060926-002/` subdirectory:

- `fork_gather_reference.py`
- `test_fork_gather_reference.py`
- `README_fork_gather_reference.md`
- `verification_test_results.txt`

The report's inline citation numbers can be matched to the citations export.
Uploaded-file citations concern an older repository snapshot, not necessarily
current code. Original `sandbox:` download links are inert historical links;
the actual supplied files are alongside the reports here.

Keep `imported/` byte-identical to these source snapshots. Its local Markdown
lint configuration disables style rules solely to preserve the imported text.
This README and the live documents use normal lint rules. Future experiments
belong outside `imported/`; do not silently repair the evidence.

## Independent verification and limitations

On 2026-09-06, the 25 supplied tests passed locally. Reproduce from the repo root:

```powershell
Push-Location 'docs/historical/research/2026-09-06-fork-gather/imported'
try { python -B -m unittest -v test_fork_gather_reference.py }
finally { Pop-Location }
```

Audit 2 explicitly labels its implementation a reconstruction: the scratch
code claimed in audit 1 was not retained. The captured output is the author's
record; the local test run is independent verification of the supplied code.
Neither is a test of `wf_core`.

The reference uses a single owner, append-only example contributions,
deep-copied transitions, and trusted in-process pickle snapshots. It does not
establish production codec validation, durable storage atomicity, arbitrary
reducers, external-effect idempotency, foreach, subgraphs, or cancellation.
Never load an untrusted pickle checkpoint.

## Known defects reproduced locally

### Repeated write execution collides

```text
w: append X -> pick
pick.again -> w
pick.done  -> END
```

`SymbolicAnalyzer` accepts this graph. Execute `w`, choose `again`, then execute
`w` using the same token. `_write()` raises
`RuntimeError: duplicate semantic contribution w@T0` because its ID uses only
node and token identity, not the execution occurrence. This is a valid loop
that the simulator must eventually execute correctly.

### Repeated gather occurrence is not rejected by analysis

```text
g.a -> h.only -> pick
pick.again -> h.only
pick.done  -> final.left
g.b        -> final.right
final      -> END
```

The supplied model permits one-port gathers. Analysis accepts the graph with
both gather anchors set to `g`. Execute `g`, fire `h`, choose `again`, then fire
`h` again: `_fire_gather_impl()` raises
`RuntimeError: duplicate merged lineage merge:h@g@T0`.
The analyzer tracks current tokens but not past firings under an unresolved
anchor. The proposed one-fire-per-occurrence contract requires validation to
reject this case. Banning one-port gathers would not prove the general rule.

Both reproductions were executed independently during review. They are not
included in the unchanged imported 25-test suite. Their regression requirements
and the next verification gates live in the draft spec, not in this archive.