Public evidence

electrical.current_divider

Machine-checked verification for calculation version 1.0.2 · tier internally_reviewed

Open calculator API Capability Download JSON CVP Manifest MCP Review policy

CVP status

Exactly two ideal resistive parallel branches; no additional branch or load. Currents are non-negative magnitudes.

Declared partition coverage: PASS · 8/8 declared partitions (from-It-R, from-I1-R, from-I2-R, from-It-I1-R1, from-It-I1-R2, underdetermined-currents, inverse-endpoint, invalid-domain)
Versions: Calculation 1.0.2 · CVP protocol 1.0.0-proposed · Evidence 2026-09-14.inverse-endpoints-schema
Verification revision: 2026-09-14.inverse-endpoints-schema · 2/2 property · digest 5836a820dfe6

Verification

Legacy regression suite: 23/23 calculation tests · Production surface contract 6/6

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 1.0.2 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 2026-09-14.inverse-endpoints-schema. Calculation version 1.0.2. CVP 1.0.0-proposed. 5/5 golden · 14/14 CVP boundary · 20/20 invalid · 2/2 property · 3/3 metamorphic · 1/1 cross-interface · 4/4 CVP contract. digest 5836a820dfe6.

Golden (oracle-backed) 5 / 5
CVP boundary 14 / 14
Invalid input 20 / 20
Property 2 / 2
Metamorphic 3 / 3
Cross-interface 1 / 1
CVP contract 4 / 4
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session.
Assurance Engineering

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 sha256:503e9a018cc00a1ca3c8546171a4ed84c28bbf686f0cc7b955d00d3e1ca1bcdc

Input schema sha256:fd2d62434ceb76f8c2f295d990f1727eac827ffc06a620cee27bd74671500934 · Output schema sha256:38d5757df93af788f9c6c92980690a4fcf9221950a9be94f3fd32febb3ec5251 · 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: current-divider
Engine: current-divider
Engine build: 2026-09-14
Evidence core: 2026-09-14T03:15:03.452Z
Rendered: 2026-11-10T05:18:41.744Z
Last reviewed: 2026-09-14

Assumptions

Exactly two ideal resistive parallel branches; no additional branch or load
DC / resistive; currents entered as non-negative magnitudes

Limitations

Exactly two ideal resistive parallel branches; no additional branch or load
Currents are non-negative magnitudes
Web UI is It+R1+R2 only
API supported combinations: It+R1+R2, R1+R2+I1, R1+R2+I2, It+I1+R1, It+I1+R2
It+I1+I2 is underdetermined → UNSUPPORTED_COMBINATION
Inverse It+I1+R1/R2 requires 0 < I1 < It for a finite R>0; I1=0 or I1=It → CURRENT_SPLIT_INVALID
It=0 and I1=0 with R1 or R2 is underdetermined → UNSUPPORTED_COMBINATION
<3 inputs → NEEDS_THREE_INPUTS

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

IEC 60050 — International Electrotechnical Vocabulary — Kirchhoff law for nodes (IEV 131-15-09)
Supports: Algebraic sum of currents at a node is zero; I1 + I2 = It for two parallel branches
IEC 60050 — International Electrotechnical Vocabulary — Resistance (IEV 131-12-04)
Supports: R = u/I on each branch; common node voltage V = I1·R1 = I2·R2
Horowitz & Hill — The Art of Electronics — 3rd ed., Cambridge University Press, 2015 — Chapter 1 Foundations, current dividers · 2015
Supports: Two-branch inverse-R current split

Methods

Algorithms this engine uses. Not external references.

Kirchhoff's current law (KCL): I1 + I2 = It
Ohm's law: V = I1·R1 = I2·R2

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.