math.fractions

Three distinct suites: educational examples on the calculator page, this legacy regression count (32/32 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 1.0.8 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 2026-10-20.fractions-complete-contract-v2. Calculation version 1.0.8. CVP 1.0.0-proposed. 10/10 golden · 8/8 CVP boundary · 9/9 invalid · 2/2 property · 1/1 metamorphic · 1/1 round-trip · 7/7 cross-interface · 6/6 CVP contract. digest 8059211bd24b.

• Golden (oracle-backed) 10 / 10
• CVP boundary 8 / 8
• Invalid input 9 / 9
• Property 2 / 2
• Metamorphic 1 / 1
• Round-trip 1 / 1
• Cross-interface 7 / 7
• CVP contract 6 / 6
• Interfaces PASS · UI (SSR) / REST / MCP
• Interface claim ui-ssr is query-result HTML, not a live browser session.
• Verified scope operate (+/−/×/÷), simplify, to-dec and from-dec
• 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 sha256:202226dcdb1309cb985e97c6d276b6c473f4ba83f1c93812b8a4f198f96811aa

Input schema sha256:454b6e55dc71046ea4bcbf5483ac86c4d82025bd005d603d51bd4b55c68cdd56 · Output schema sha256:d451b0103e2d597a9c2cb024fadad14d981603f09616ad1a288ee1780ccfb850 · 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

fractions

Engine

fractions

Engine build

2026-10-20

Evidence core

2026-10-20T13:36:01.263Z

Rendered

2026-10-21T01:08:25.775Z

Last reviewed

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Assumptions

• Fraction inputs and every arithmetic intermediate must be safe integers (absolute value at most 2^53−1); otherwise VALUE_OUT_OF_RANGE.
• From decimal converts the shortest normalized binary64 decimal exactly within the reduced safe-integer envelope; all four modes are in the current numerical verification scope.
• Results reduced by GCF; signs normalized onto the numerator.

Limitations

• Integer numerators and denominators only (optional mixed-number whole)
• Denominator 0 → DENOMINATOR_MUST_BE_NONZERO
• Division by 0/n → DIVISION_BY_ZERO
• Add/subtract use LCD = LCM(b, d); (ad ± bc)/bd is an equivalent check only
• Negative sign is normalized onto the numerator after reduction
• Expert review pending — L1 engine-tested / source-checked
• Required numerator/denominator or decimal never default; whole alone may be absent/empty. Unknown mode/op/field and conflicting aliases rejected.
• From-dec uses shortest decimal serialization after binary64 normalization, not the exact binary float fraction. Nonzero-to-zero rejected; reduced numerator and denominator must be safe integers.
• rational_exact describes n/d; decimal/decimal_display are rounded previews (12 significant digits normally,9 scientific). Full structured result available in native exports.