Blocked calculation inspection model

This additive candidate lets the Evidence workbench display source-bound calculation dependencies. It does not calculate a Pension Credit award, decide entitlement, request claimant details or change any of the 40 retained evidence packages. The model is an authored, unreviewed proposal. Every cited package remains insufficient and truncated.

Rebuild and inspect

uv sync --locked
uv run --locked python scripts/build_workbench_models.py
uv run --locked python scripts/build_workbench_models.py --check
uv run --locked python -m unittest discover -s scripts -p test_workbench_models.py -v

The authored input is inspection.json. The producer checks the original workbench manifest SHA-256, each cited package SHA-256, selected record ID, assertion status, source URL, PDF page locator, source and literal hashes, capture time, unit-boundary status and a short exact text snippet. These checks compare the proposal with the retained, hash-bound package; they do not rehash the official PDFs or rerun source extraction. It then creates tools-manifest.json with the original 40 questions and package references unchanged. This successor manifest is an opt-in source file for Explorer; it is not part of the version 3 learning-site publication allowlist. A consumer should use an immutable DWP Git revision and verify its manifest digest. The projection is under Explorer's 256 KiB manifest limit.

The calculation_models and interaction_proposals fields follow Explorer's CalculationModel and InteractionProposal contracts. The model status is always blocked, its authority is authored-unreviewed-proposal, its jurisdiction and effective dates are null, and there is no formula or arithmetic field. The source snippets are verification anchors, not executable expressions. required: null records that mandatory facts have not been settled. Units distinguish capital stock (GBP) from weekly income (GBP/week) without implying a rate or calculation.

Try the five data tabs

The reviewed model manifest was merged in DWP PR 39, and the compatible Explorer workbench in Explorer PR 146. Use the workbench launch link to load the immutable tools-manifest.json and its unchanged packages/ and parts/ neighbours. Older links retain their original catalogue. This raw GitHub delivery is separate from the bounded learning-site publication.

1. Open staff-016 (“Given these inputs what is the formula for calculating Pension Credit?”). The package itself says insufficient; the model is blocked.
2. Use Graph to inspect directed retained relationships and their source references. An edge is not automatically a calculation dependency.
3. Use Interactions on staff-039. Read the separate carer-income, carer-addition and cared-for-person directions, and the Chapter 17 overlap reference. Do not reverse an arrow or infer an award change.
4. Use Requirements to see the missing input, applicability, legal-version and review obligations. A selected passage does not close these requirements.
5. Use Rates to see that no reviewed typed rates contract or effective period is admitted. To inspect a number mentioned in guidance, follow its source passage separately; do not use an historic example as a current rate.
6. Use Calculation stages to inspect the five input groups and five source-linked stages. It reports blocked, unknown required fields, null effective dates and explicit gaps. It cannot accept personal details or return an amount.

These are the five data tabs (graph, interactions, requirements, rates, calculation). The original source, extraction, passage, ontology, definitions, trace and review tabs remain useful for checking the underlying evidence.

Try the seven page tools

In a compatible browser, a page may register seven WebMCP tools. Start with okf_get_state to obtain the current snapshot and page revision. Use okf_search_evidence to find staff-015, staff-016 or staff-039; okf_get_evidence to read one selected passage and its provenance; okf_get_relationships to inspect directed assertions; okf_get_view_data to obtain a bounded table or graph for one of the five data tabs; okf_get_calculation to inspect the blocked model by ID or stage; and okf_show_view to display a referenced case or record. State-changing presentation uses the current snapshot and revision; a stale call should be rejected and retried from okf_get_state.

For example, a reviewer can search for “Pension Credit formula”, open staff-016, request the calculation data view, then call okf_get_calculation with model ID pension-credit-source-inspection-v1 and section inputs or stages. The result should identify evidence and gaps, not an award. A separate staff-039 journey can show why Carer’s Allowance effects must be read by direction and by person. Each tool response should be checked against its snapshot ID and source links; a compact response may require continuation.

On their own, registration or local tool tests do not prove that an assistant panel can discover or invoke the page tools. Native browser registration, actual host invocation, rendered page state and any panel visualisation need separate observations. The workbench remains usable through its ordinary controls when WebMCP is unavailable.

The 24 September sidebar demonstration records successful native tool calls and visible page changes from Edge's ChatGPT sidebar through its existing developer connection. That observed route is separate from automatic discovery through a dedicated WebMCP connection.

Source-led inspection stages

The selected records retain official PDF URLs, page locators, source hashes and literal-span hashes. Their unit boundaries are machine-detected and completeness is unresolved. A PDF capture date is not an effective date. Examples and historic figures in extracted passages are not current rates.

The separate GOV.UK adviser guide (April 2026, updated 8 May 2026) describes a Guarantee Credit calculation sequence, dated rates, Savings Credit Amount A/B and worked examples. It is a useful source lead for a future bounded, versioned acquisition and review. Its page content has not been admitted to this frozen package or model, so it does not change the blocked status or supply executable rates here.

For Carer’s Allowance, the source proposes separate directions: CA may enter the carer’s own income assessment (DMG 85091); CA entitlement or treated qualifying conditions may lead to the carer’s own Pension Credit carer additional amount (DMG 78105); CA or a UC carer element in payment for caring for the claimant or partner may affect the cared-for person’s severe-disability additional amount (DMG 78057). DMG 60109 only points to Chapter 17 for overlapping benefits; the retained passage does not decide another benefit's outcome. These are directional, qualified review prompts, not a symmetric interaction rule or award result.

What blocks execution

The source-linked stages do not establish a complete input contract, versioned rates, jurisdiction, legal applicability, exceptions, precedence, ordering or rounding. Savings Credit and special-group provisions need separate review. All four relevant staff packages (010, 015, 016 and 039) explicitly retain missing evidence and insufficient status. Source closure and independent specialist review are required before a rule or calculation could be approved. The repository's current prohibition on individual awards and claimant data remains in force.

The separately supplied Guarantee Credit calculation brief (research/overview-of-how-guarantee-credit-is-calculated.md in the owner's checkout) asks for a future chain of source passage → proposition → reviewed rule and calculation model → deterministic Java implementation → scenario → explanation. Each future Java rule would need a stable ID, legal version and effective period, source passage/page/hash, dependencies, exception precedence, units, rounding, source-derived tests and reviewer decision. A later MongoDB service would need separate valid time for the benefit circumstances and recorded time for when a change was stored, immutable rule/model versions, replayable retrospective events and controlled query access. Projection without persistence would use the same approved deterministic engine but would not store the hypothetical scenario. None of that backend is implemented by this manifest.

A future synthetic calculation demonstrator needs a separately reviewed scope and an explicit amendment to the project agreement or architecture decision record. It must remain separate from operational use with real claimant data. The current workbench model is safe to inspect precisely because execution stays blocked.