math.subtraction

Three distinct suites: educational examples on the calculator page, this legacy regression count (7/7 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 2026-10-22.subtraction-complete-contract-v3. Calculation version 1.0.2. CVP 1.0.0-proposed. 82/82 golden · 1/1 CVP boundary · 5/5 invalid · 2/2 property · 1/1 metamorphic · 2/2 round-trip · 7/7 cross-interface · 6/6 CVP contract. digest a0f1f4f1c566. 82 independent complete packs across binary64 missing-term and exact bounded decimal Long branches; no exhaustive-domain proof.

• Golden (oracle-backed) 82 / 82
• CVP boundary 1 / 1
• Invalid input 5 / 5
• Property 2 / 2
• Metamorphic 1 / 1
• Round-trip 2 / 2
• 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. Error-path engine·REST·MCP 1/1 (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.
• 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 sha256:3858ac9946c6434a2f06373ccf5b0f8268ce418b3d6c773730867d010f9a7395

Input schema sha256:9c1ec7b28cf3db713c746af9b7c016edd000313cd43b41beef982823a07ce98c · Output schema sha256:e09c05e6abaec6df6a02613c008f543607e5cd1e7174e36a5cceb8bf92951299 · 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

subtraction

Engine

subtraction

Engine build

2026-10-22

Evidence core

2026-10-22T10:03:41.853Z

Rendered

2026-10-23T01:27:11.574Z

Last reviewed

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Assumptions

• Difference mode: binary64 arithmetic; exactly two terms; scientific notation allowed; integral inputs within ±(2^53−1).
• Long subtraction: non-negative decimal numbers without scientific notation.
• Order is minuend − subtrahend. When minuend < subtrahend the difference is negative; long mode still stacks the minuend on top. Column work subtracts the smaller magnitude from the larger, then applies the sign.

Limitations

• Difference requires exactly two terms and uses binary64, not exact decimal arithmetic. All normalized integral operands must be safe integers. Cancellation may amplify input/conversion error; measurement uncertainty is not modeled.
• Long uses exact decimal strings; display and exact_value are authoritative. Numeric fields are approximate binary64 conveniences. Up to48 aligned columns, non-negative inputs, negative result allowed; no scientific notation.
• Tokens at most512 characters, without commas. Unknown fields, invalid types/modes, conflicting aliases and text nonzero underflow rejected.
• Shared links run the current engine; they do not retain historical runtimes.