Public evidence

engineering.conformity.mpe

Machine-checked verification for calculation version 1.0.1 · tier engine_tested

Open calculator API Capability Download JSON CVP Manifest Reproduce MCP Review policy

CVP status

Not En. O3 tabulated vectors only.

Declared partition coverage: PASS · 5/5 declared partitions (alias, awkward, pass, fail, invalid-domain)
Versions: Calculation 1.0.1 · CVP protocol 1.0.0-proposed · Evidence 2026-09-25.o2-o3
Verification revision: 2026-09-25.o2-o3 · 1/1 property · digest c1588f98a65e

Verification

Legacy regression suite: 9/9 calculation tests · Production surface contract 6/6

Three distinct suites: educational examples on the calculator page, this legacy regression count (9/9 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-25.o2-o3. Calculation version 1.0.1. CVP 1.0.0-proposed. 4/4 golden · 5/5 CVP boundary · 5/5 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract. digest c1588f98a65e. O2: MPE ratio vs a separate-module identity (≤2 ULP). Not En. ≤2 ULP vs O3 applies only to the published tabulated MPE vectors. Not En.

Golden (oracle-backed) 4 / 4
CVP boundary 5 / 5
Invalid input 5 / 5
Property 1 / 1
Metamorphic 1 / 1
O3 high-precision 8 / 8
Cross-interface 2 / 2
CVP contract 6 / 6
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
Verified scope MPE ratio |ylab − xref| / MPE, with equality counted as pass, + O3 mpmath tabulated MPE.
Assurance Engineering
Deferred Not En and not an ILAC G8 guard band.

release artifacts aligned PASS
schema output required declared PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS
rest success payload validates schema PASS

Fingerprint sha256:58f1eed9d913687d9b848ca259e813d3c05153edd95391f53d91a39790cab02e

Input schema sha256:97902045444aeb0f07e3272599fe810504ecc7a90ae0377bc71f0f58b7e51ed9 · Output schema sha256:9cd4fefc2b226695a42f7dbc23b3c412f0f8c1e1e931f9c271d7651d0354f97d · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: mpe
Engine: mpe
Engine build: 2026-09-24
Evidence core: 2026-09-24T22:27:15.413Z
Rendered: 2026-10-23T01:27:11.173Z
Last reviewed: —

Assumptions

VIM maximum permissible measurement error: pass iff |ylab−xref| ≤ MPE
Equality is pass. ratio = |ε|/MPE
Not an ILAC G8 spec decision on y, not En, and not ε without a limit
U, Ulab, and T are not aliases for MPE

Limitations

Binary |ε| ≤ MPE — equality is pass
Does not compare y to LSL/USL (use the decision-rule page)
Does not divide by U (that is En) and does not report ε without a limit
U, Ulab, and T are not aliases for MPE

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

JCGM 200:2012 — International vocabulary of metrology (VIM) — 4.26 maximum permissible measurement error (maximum permissible error, limit of error)
Supports: MPE is the extreme value of measurement error permitted by specifications or regulations. Pass iff |ε| ≤ MPE.
ISO 14253-1 — Geometrical product specifications (GPS) — Inspection by measurement of workpieces and measuring equipment — Decision rules vs MPE of a measuring equipment
Supports: MPE is a stated error limit of the measuring equipment, not an ILAC G8 specification decision on the workpiece characteristic y

Verification disclosure

Aggregate outcomes, scope and artifact commitments are public. Complete test inputs, expected values, execution records and oracle infrastructure are retained privately. This summary does not independently reproduce the full verification run.