# mutually-exclusive-terminal-payout

> Terminal payout remains reachable after a mutually exclusive one-time milestone.

Canonical: https://nightshade.dicksonwu.xyz/rules/mutually-exclusive-terminal-payout.html
Release: Nightshade 0.1.1 (v0.1.1)

| Field | Value |
| --- | --- |
| Rule ID | `mutually-exclusive-terminal-payout` |
| Severity | high |
| Confidence | high |
| Maturity | experimental |
| Selection | Opt-in |
| Policy intent | not required |
| Default enabled | no |
| Category | Other active opt-ins / State and collections |
| Engine facts used | runtime-operations, state-writes, completed-entries |
| Release | v0.1.1 |

## Selection and scope

Not selected by default. Select it with `--detectors` or the `detectors` list in nightshade.json. Either one replaces profile selection, so list every rule you want.

```sh
./.nightshade/node_modules/.bin/nightshade ./contracts --detectors mutually-exclusive-terminal-payout
./.nightshade/node_modules/.bin/nightshade detector show mutually-exclusive-terminal-payout
```

The first command runs only this rule; `--detectors` takes a comma-separated list. The second prints the rule's metadata from your installed version.

Severity is review priority. It does not express exploitability or impact. Confidence is detector metadata, not a probability. All built-in rules are experimental.

Compiler scope: the engine supports the pinned profiles 0.28.0, 0.29.0, 0.30.0, 0.31.1, 0.33.0-rc.2, 0.34.0, 0.35.0-rc.1 and 0.35.0, with ZKIR2 by default. Support for this rule can be narrower; the rule documentation below states any narrower scope.

## Corpus checks

Synthetic corpus checks for this rule in the 0.1.1 proof run. A check counts only with compiler acceptance and complete analysis.

| Positive detected | Corrected quiet | Lookalike quiet | Other negative quiet | Incomplete |
| ---: | ---: | ---: | ---: | ---: |
| 1/1 | 1/1 | 1/1 | 0/0 | 0 |

No deviations were recorded for this rule.

These are behavior checks on synthetic fixtures, not a precision or recall estimate. See [evaluation](https://nightshade.dicksonwu.xyz/evaluation.md#synthetic-corpus).

## Rule documentation

From https://github.com/DicksonWu654/nightshade/blob/v0.1.1/docs/detectors/mutually-exclusive-terminal-payout.md at v0.1.1.

Availability: **opt-in state-machine/effect review**, no policy required. Severity/confidence: **high/medium**.

The rule finds a sibling one-time milestone transition (a represented Boolean
false-to-true write) and a timeout/refund/release-style exported circuit that
performs a canonical token payout and terminal-state write without reading the
milestone state. It recognizes standard-library send lowering and reports the
user call site. This is a cross-entry continuation review: censorship assumptions,
commercial policy and runtime asset custody remain unproved.

An application may intentionally allow the payout independently of a sibling
milestone, or may use the state solely for off-chain coordination; either can
produce a valid review match. The rule compares source-level entry effects. It
does not prove transaction ordering, simultaneous reachability, custody loss, or
that the milestone is the application's intended completion condition.

## Suppress a match

If a match is intentional, suppress it on the line before with the exact rule ID and a reason of at least eight characters:

```compact
// nightshade-disable-next-line mutually-exclusive-terminal-payout -- Reason this match is intentional
```

Diagnostics cannot be suppressed, and an unmatched directive for a selected rule makes analysis incomplete. See [configuration](https://nightshade.dicksonwu.xyz/configuration.md#suppress-an-intentional-match) for fingerprint suppressions and baselines.

## References

- [Rule source document at v0.1.1](https://github.com/DicksonWu654/nightshade/blob/v0.1.1/docs/detectors/mutually-exclusive-terminal-payout.md)
- [Catalog entry in rules.json](https://nightshade.dicksonwu.xyz/rules.json)
- [All rules](https://nightshade.dicksonwu.xyz/rules.md#state-and-collections)
- [Limitations](https://nightshade.dicksonwu.xyz/limitations.md)