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Public evidence

math.transform.z

Machine-checked verification for calculation version 1.0.5 · tier engine_tested

CVP status

CVP VERIFIED · CVP protocol 1.0.0-proposed · Core assurance · all published modes

Unilateral table: a^n, step, ramp, n a^n, sin, cos, damped sin/cos. Discovery /inverse-z. Not DFT, not Laplace, not residue, not CAS.

Declared partition coverage
PASS · 3/3 declared partitions (z, inverse, invalid-domain)
Versions
Calculation 1.0.5 · CVP protocol 1.0.0-proposed · Evidence 2026-10-19.z-input-contract-review
Verification revision
2026-10-19.z-input-contract-review · 1/1 property · digest d640971981ed

Verification

Legacy regression suite: 10/10 calculation tests · Production surface contract 5/5

Three distinct suites: educational examples on the calculator page, this legacy regression count (10/10 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 1.0.5 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 2026-10-19.z-input-contract-review. Calculation version 1.0.5. CVP 1.0.0-proposed. 656/656 golden · 2/2 CVP boundary · 22/22 invalid · 1/1 property · 26/26 cross-interface · 5/5 CVP contract. digest d640971981ed.

  • Golden (oracle-backed) 656 / 656
  • CVP boundary 2 / 2
  • Invalid input 22 / 22
  • Property 1 / 1
  • Cross-interface 26 / 26
  • CVP contract 5 / 5
  • Interfaces PASS · UI (SSR) / REST / MCP
  • Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 8/8 (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. Raw HTTP REST/JSON-RPC transport rejection 5/5; raw-number source and conflicting pins are transport-only checks, not engine/SSR input-source parity.
  • Verified scope all published modes
  • 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:be350c6e5294e38606b4543367a8414cd5dcbda201bd0d888fdbb5898863e707

Input schema sha256:ebd54d7d106e805d80e71d4c780d0400240bde37381cdd525886c1a255b7b054 · Output schema sha256:7407c126a1622690e6057ae9621f4ae9b6f472724961bd5b820cfb94fe30b244 · 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
z-transform
Engine
z-transform
Engine build
2026-10-19
Evidence core
2026-10-19T03:14:53.616Z
Rendered
2026-10-23T01:27:11.647Z
Last reviewed
—

Assumptions

  • Unilateral, causal n≥0
  • Real z in the ROC
  • Table of named pairs, not a CAS
  • The Result Card includes an engine-linked figure of X(z) on the real ROC (pole at |z|=|a|) or a stem of x[n] (at most 16 indices). Same table as REST/MCP.
  • Not DFT / FFT
  • Not Laplace
  • Not residue / two-sided
  • Not a pole-zero Argand of complex z

Limitations

  • Unilateral causal elementary table; eight named pairs, inverse integer0–64; u[0]=1,a^0=1 including a=0
  • Finite real z strictly outside conservative ROC radius on either real branch, including degenerate zero sine; a,z dimensionless, omega radians per sample
  • Binary64 approximate evaluation,12 significant digits;2e-11 relative fixture tolerance, no uniform accuracy theorem; conditioned near poles and trig zeros
  • Coded decimal input underflow and numerical range/phase/quantization refusals; inverse subnormal relative precision may be refused despite representability
  • Aliases must agree; null, nondecimal scalar forms and unknown fields rejected; inverse URL locks mode
  • Arbitrary symbolic sequence and contour/residue inversion are outside this named table

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.