math.log

Three distinct suites: educational examples on the calculator page, this legacy regression count (45/45 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 1.1.6 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 2026-09-08.xcal. Calculation version 1.1.5. CVP 1.0.0-proposed. 3/3 golden · 23/23 CVP boundary · 23/23 invalid · 2/2 property · 2/2 metamorphic · 3/3 round-trip · 14/14 O3 · 1/1 cross-interface · 12/12 cross-calculator · 4/4 URL→result→graph · 3/3 CVP contract. digest f983352a55ff. ≤2 ULP vs O3 applies to the 14 published tabulated common-log vectors (log₁₀ of 1, 10, 100, 0.1, 2, 1000 plus 8 seeded random x = 10^(u·6−2) in about [0.01, 10⁴]). It is not a guarantee over all bases, the whole positive reals, or unlisted neighborhoods of 0 and 1.

• Golden (oracle-backed) 3 / 3
• CVP boundary 23 / 23
• Invalid input 23 / 23
• Property 2 / 2
• Metamorphic 2 / 2
• Round-trip 3 / 3
• O3 high-precision 14 / 14
• Cross-interface 1 / 1
• Cross-calculator 12 / 12
• URL → result → graph 4 / 4
• CVP contract 3 / 3
• 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 output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• rest success payload validates schema PASS

Fingerprint sha256:bcb7a82f169cf93207a2650382b83eb6ff3e999dc0f1b4d87181c3b4ff5d8ad2

Input schema sha256:7d087522bac508a630ba719d929a8cfa2f64c8522e6ea08ee051bd5d4cd66b7c · Output schema sha256:8ff71d8c30e992a2dbca0e8d464116bdd8233e7a9de147a2689611f33b5a42ca · 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

log

Engine

log

Engine build

2026-10-14

Evidence core

2026-10-14T02:50:33.742Z

Rendered

2026-10-27T01:16:26.924Z

Last reviewed

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Assumptions

• Real arithmetic; argument x > 0; base b > 0 and b ≠ 1.
• Unspecified log is common (base 10). ln is the dedicated natural-log page; this engine also accepts base e.
• UI, SSR share URLs, REST, and validation cases all call this same three-mode engine.
• When b, x, and y are all present with no explicit solve_for, the engine computes y and ignores the extra y (legacy share URLs).

Limitations

• Real logarithm only: x > 0; b > 0 and b ≠ 1 (including 0 < b < 1)
• Missing scalar → MISSING_REQUIRED_INPUT / INVALID_NUMBER
• Invalid base → INVALID_BASE; x ≤ 0 → INVALID_ARGUMENT
• Solve-for-b edge cases → NON_UNIQUE_BASE / NO_REAL_SOLUTION / RESULT_OVERFLOW