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Public evidence

engineering.uncertainty.type_a

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

CVP status

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · Type A u_A = s/√n from a sample (Bessel ddof=1 default, population ddof=0) + O3 mpmath tabulated mean/s/u_A. CSV/JSON/array and sample alias.

Single-sample Type A. Not GUM combination. O3 tabulated vectors only.

Declared partition coverage
PASS · 7/7 declared partitions (bessel, population, csv, json, sample-alias, constant, invalid-domain)
Versions
Calculation 1.0.0 · CVP protocol 1.0.0-proposed · Evidence 2026-09-16.o2-o3
Verification revision
2026-09-16.o2-o3 · 2/2 property · digest 091eb0d8d4cd

Verification

Legacy regression suite: 7/7 calculation tests · Production surface contract 6/6

Three distinct suites: educational examples on the calculator page, this legacy regression count (7/7 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 1.0.0 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 2026-09-16.o2-o3. Calculation version 1.0.0. CVP 1.0.0-proposed. 6/6 golden · 3/3 CVP boundary · 7/7 invalid · 2/2 property · 2/2 metamorphic · 8/8 O3 · 4/4 cross-interface · 4/4 CVP contract. digest 091eb0d8d4cd. O2: mean / sample s / u_A = s/√n vs separate-module identities (≤2 ULP). Not GUM combination, not SEM product page, not Monte Carlo. ≤2 ULP vs O3 applies only to the published tabulated Type A vectors (Bessel, population, scale, constant, two-point, n=5, centered, default ddof). It is not a whole-domain sample-statistics guarantee.

  • Golden (oracle-backed) 6 / 6
  • CVP boundary 3 / 3
  • Invalid input 7 / 7
  • Property 2 / 2
  • Metamorphic 2 / 2
  • O3 high-precision 8 / 8
  • Cross-interface 4 / 4
  • CVP contract 4 / 4
  • 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 Type A u_A = s/√n from a sample (Bessel ddof=1 default, population ddof=0) + O3 mpmath tabulated mean/s/u_A. CSV/JSON/array and sample alias.
  • Assurance Engineering
  • Deferred Not GUM RSS of several uᵢ, not expanded U=k·u_c, not Monte Carlo, and not a standalone SEM product page.
  • 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:abbbbc01e87248308a204e5238109d9a34f5b23acb2bb4d4f12993d725f5fe38

Input schema sha256:8cd2753b3d27d89ca2d63c7fc2d854103e5aa4db1d51e454eb70909d76d2ec82 · Output schema sha256:81b14f1a196e3f3448dddad91670038b910b106a21811ced1c5b0f62eb86b714 · 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
type-a
Engine
type-a
Engine build
2026-09-16
Evidence core
2026-09-16T21:07:40.795Z
Rendered
2026-11-10T05:18:41.778Z
Last reviewed
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Assumptions

  • Type A: u_A = s/√n from summarizeSample (ddof=1 default)
  • Not GUM combination of several uᵢ
  • Not Monte Carlo
  • Independent repeated observations of one quantity

Limitations

  • Type A from a sample — not GUM RSS of several uᵢ
  • Not Monte Carlo
  • ddof=1 requires n≥2

Sources

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

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.