# Experiment 60B.30 — `Uncertainty over whether...` Proposition Coverage

**Branch:** `feature/proposition-prefix-over-v0.32`  
**Starting HEAD:** `35a5efa80480eb00e69b1004f33e20330fe2434e`  
**Date:** 2026-08-14  
**Status:** COMPLETE

## Objective

Close the narrow live coverage gap exposed by 60B.29 by extending the existing bounded proposition-prefix normalization so:

```text
Uncertainty over whether X...
```

enters the same `whether ...` proposition-extraction path already used for:

```text
Whether X...
Unknown whether X...
Uncertain whether X...
Uncertainty about whether X...
Uncertainty regarding whether X...
```

## 60B.29 Live Gap

60B.29 preserved the full reasoning chain live but surfaced a new bounded synonym form in the node description:

```text
Uncertainty over whether the prospective enterprise customer will sign if we launch this year, because their contract accounts for approximately £700,000 of the expected first-year revenue and could materially flip the net-value comparison.
```

Because `uncertainty over` was not part of the existing normalization boundary, deterministic formulation did not expose:

```text
whether the prospective enterprise customer will sign if we launch this year
```

to the established evidence-framed proposition path.

## Exact Normalization Added

Production change was limited to `lib/graph/question-formulator.js`.

Inside `extractMeaning()`, the description-start normalization used before the existing `^whether` proposition check now also strips:

```text
uncertainty over
```

case-insensitively.

This means the following bounded forms are now equivalent for proposition extraction:

```text
Whether X...
Unknown whether X...
Uncertain whether X...
Uncertainty about whether X...
Uncertainty regarding whether X...
Uncertainty over whether X...
```

Each now exposes:

```text
whether X
```

before the existing rationale stripping and evidence framing run.

## Exact 60B.29 Deterministic Regression

For:

```text
label:
Prospective enterprise customer signing status

description:
Uncertainty over whether the prospective enterprise customer will sign if we launch this year, because their contract accounts for approximately £700,000 of the expected first-year revenue and could materially flip the net-value comparison.
```

the deterministic final question is now:

```text
What evidence would clarify whether the prospective enterprise customer will sign if we launch this year?
```

The final question excludes:

- `£700,000`
- `expected first-year revenue`
- `materially flip`
- `because their contract`

and the source description remains unchanged.

## Focused Verification

Run exactly as bounded:

```bash
npx vitest run tests/graph/question-formulator.test.js
```

Result:

```text
PASS — 39/39 tests
```

Focused coverage confirms:

- exact 60B.29 regression passes
- `Uncertainty over whether...` without rationale uses evidence framing
- previously-supported prefixes remain unchanged
- direct interrogatives remain unchanged
- nominal non-`whether` behaviour remains unchanged
- source description remains intact

## Preserved Existing Paths

This change did **not**:

- redesign question formulation
- broaden parsing beyond one explicit uncertainty synonym
- add domain-specific wording
- change decision-family routing
- change question-target selection
- change graph structure, materiality, schema, provider, or harness behaviour

## What Remains Unproven

Deterministic coverage for `Uncertainty over whether...` is now proven, but the exact full live 60B.29 rerun on this branch remains to be executed.