math.ln

Three distinct suites: educational examples on the calculator page, this legacy regression count (23/23 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 1.0.4 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 2026-09-08.xcal. Calculation version 1.0.4. CVP 1.0.0-proposed. 3/3 golden · 12/12 CVP boundary · 12/12 invalid · 2/2 property · 2/2 metamorphic · 3/3 round-trip · 16/16 O3 · 1/1 cross-interface · 12/12 cross-calculator · 4/4 URL→result→graph · 1/1 CVP contract. digest eafd28643bc3. ≤2 ULP vs O3 applies to the 16 published tabulated natural-log vectors. It is not a guarantee over the whole positive reals or unlisted neighborhoods of 0 and 1.

• Golden (oracle-backed) 3 / 3
• CVP boundary 12 / 12
• Invalid input 12 / 12
• Property 2 / 2
• Metamorphic 2 / 2
• Round-trip 3 / 3
• O3 high-precision 16 / 16
• Cross-interface 1 / 1
• Cross-calculator 12 / 12
• URL → result → graph 4 / 4
• CVP contract 1 / 1
• Interfaces PASS · UI (SSR) / REST / MCP / URL→result→graph
• Interface claim Success 1/1. Integration: URL → SSR result → Live graph current point (4/4). Hydration/slider/history are URL-canonical contracts, not a live browser session.
• Assurance Core

• release artifacts aligned PASS
• schema valid input executes PASS
• engine success output validates schema PASS

Fingerprint sha256:61a83a4f0bd289e5279485b0066d05c06eede305d63e15a9444869c77b4fed0e

Input schema sha256:3f55c5f8e53ba82bab2921c6040dbd50d054268f639f54840035cae6e2e7ccb3 · Output schema sha256:3abb8d269c34a106dea9abf33c25f35b9e2cccfb53c7579ae1a660d382f3f4a5 · 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.

Tool

ln

Engine

ln

Engine build

2026-09-10

Evidence core

2026-09-10T22:48:17.762Z

Rendered

2026-09-16T22:03:43.776Z

Last reviewed

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Assumptions

• Real arithmetic; argument x > 0. Base is e, not 10.
• On many calculators log means log₁₀; in some programming languages log(x) means ln(x).
• Published engine is y = ln(x). A legacy y query parameter is ignored and stripped from the address bar. Inverse x = e^y is Antilog with base e.

Limitations

• Real ln only: x > 0 → INVALID_ARGUMENT when x ≤ 0
• Missing x → MISSING_REQUIRED_INPUT; non-finite → INVALID_NUMBER