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Public evidence

math.square_root

Machine-checked verification for calculation version 1.0.3 · tier engine_tested

Historical evidence. This page is version 1.0.3 · engine_tested · 18/18 tests. It is not the current published claim. Current evidence is 1.0.4 (18/18 tests) · latest.

CVP status

CVP VERIFIED · production STALE · CVP protocol 1.0.0-proposed · Core assurance

Declared partitions are positive-real, zero, negative-imaginary, tiny-subnormal, large-finite, invalid-domain — not a whole-domain claim. x < 0 is the published principal imaginary √|x| i, not invalid-domain. O3 ULP covers the tabulated non-negative vectors plus principal imaginary -9/-2, min-subnormal, and max-finite.

Declared partition coverage
PASS · 6/6 declared partitions (positive-real, zero, negative-imaginary, tiny-subnormal, large-finite, invalid-domain)
Versions
Calculation 1.0.3 · CVP protocol 1.0.0-proposed · Evidence 2026-09-09.o3-boundary
Verification revision
2026-09-09.o3-boundary · 4/4 property · digest aa716638904c

Verification

Legacy regression suite: 18/18 calculation tests · Production surface contract 5/5

Three distinct suites: educational examples on the calculator page, this legacy regression count (18/18 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.

    STALE · Build schema 1.0.4 matches page · production binding STALE · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · CVP STALE · attestation STALE — Production CURRENT withheld · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-09.o3-boundary. Calculation version 1.0.3. CVP 1.0.0-proposed. 7/7 golden · 7/7 CVP boundary · 7/7 invalid · 4/4 property · 2/2 metamorphic · 3/3 round-trip · 21/21 O3 · 7/7 cross-interface · 5/5 URL→result→graph · 1/1 CVP contract. digest aa716638904c. ≤2 ULP vs O3 applies to the published tabulated Square Root vectors, including non-negative named and seeded values, principal imaginary of -9 and -2, IEEE-754 min-subnormal, and max-finite. It is not a guarantee over the entire input domain.

  • Golden (oracle-backed) 7 / 7
  • CVP boundary 7 / 7
  • Invalid input 7 / 7
  • Property 4 / 4
  • Metamorphic 2 / 2
  • Round-trip 3 / 3
  • O3 high-precision 21 / 21
  • Cross-interface 7 / 7
  • URL → result → graph 5 / 5
  • CVP contract 1 / 1
  • Interfaces PASS · UI (SSR) / REST / MCP / URL→result→graph
  • Interface claim Success 4/4. Error-path engine·REST·MCP 3/3 (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. Integration: URL → SSR result → Live graph current point (5/5). Hydration/slider/history are URL-canonical contracts, not a live browser session. Live-browser hydration, slider, Copy JSON, and Overview/Focus are not Core CVP. They are covered by npm run test:math-graph-e2e (MATH_GRAPH_E2E_ONLY=square_root).
  • Assurance Core
  • release artifacts aligned PASS
  • schema output required declared PASS
  • schema valid input executes PASS
  • engine success output validates schema PASS
  • rest success payload validates schema PASS

Fingerprint sha256:01a95214633a22c075abfe506188cc7661a6d663cf51ab4754c55d1807615663

Input schema sha256:ff1cf6b2f9ee1b970abddef0da1ea9f8523f33da2149c3b96c0f0cd1ca3b6aec · Output schema sha256:5d98f7f033a8be30482d03b3180c7f013da86b33a56a0b85893efef90e0bee63 · 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
square-root
Engine
square-root
Engine build
2026-10-14
Evidence core
2026-10-14T02:50:33.742Z
Rendered
2026-10-26T04:58:53.676Z
Last reviewed
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Assumptions

  • Principal branch: nonnegative real root when x ≥ 0.
  • Unlike Log / Ln, this engine does not reject x < 0. It returns the principal imaginary √|x| i, not a real error.
  • The other real root for x > 0 is −√x; the other imaginary root for x < 0 is −√|x| i. The published value is the principal one.

Limitations

  • x ≥ 0 → principal = √x, imag = 0
  • x < 0 → real = 0, imag = √|x|, principal = null (unlike math.root NOT_REAL)
  • Missing x → MISSING_REQUIRED_INPUT

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.