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.

STALE · Build schema 1.0.5 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 2026-10-28.meta-metrics-v2. Calculation version 1.0.5. CVP 1.0.0-proposed. 36/36 golden · 12/12 CVP boundary · 12/12 invalid · 2/2 property · 2/2 metamorphic · 3/3 round-trip · 16/16 O3 · 4/4 cross-interface · 12/12 cross-calculator · 4/4 URL→result→graph · 6/6 CVP contract. digest 5d40bfcffb9c. ≤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.; plus33 Decimal180 complete-pack references, primary4ULP and inverse16 EPS max(1,|y|) relative plus2subnormal quanta.

• Golden (oracle-backed) 36 / 36
• 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 4 / 4
• Cross-calculator 12 / 12
• URL → result → graph 4 / 4
• CVP contract 6 / 6
• Interfaces PASS · UI (SSR) / REST / MCP / URL→result→graph
• Interface claim Success 1/1. 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 (4/4). Hydration/slider/history are URL-canonical contracts, not a live browser session.
• Assurance Core

• 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 sha256:4ee33abafd497aa8a762568d58003165321e2cbb1d5a5691e59b87fd26e59663

Input schema sha256:2a8b0c1068f0f7a4c9bf3dec7f71eb8d42116d06330877ba2e153d270b254158 · Output schema sha256:c74a38e7e8eaaf2cd789f297ca082260e2d10430aa2e61965c4ac6447c44471b · 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

2026-10-27

Evidence core

2026-10-27T01:28:20.603Z

Rendered

2026-10-28T03:01:57.872Z

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

• Positive finite binary64 x or symbolic e; strict decimal/scientific text ≤512 characters; nonzero text rounded to zero rejects NUMERIC_UNDERFLOW. Unknown keys/conflicting x aliases reject. Legacy y/yInput ignored.
• Math.log approximates normalized binary64 inputs. Exact flag only x=1 or symbolic e. Display 12 significant digits; native exports retain full pack and input text.
• Independent Decimal180 vectors accept logarithms within4 ULP and inverse values within16 EPS max(1,|y|) relative plus2 subnormal quanta. Existing16 O3 vectors retain2 ULP; neither claim covers the whole domain.
• Near1 input rounding is ill conditioned; inverse check tolerance128 EPS max(1,|y|) relative plus2 subnormal quanta is not exactness proof.
• Typing local; shared URLs/REST/MCP send inputs and may enter logs. Slider0.1–10 only; Focus graph bounded around current input.