Home Developers Capabilities Euclidean remainder / modular inverse

CVP verified calculation capability

Euclidean remainder / modular inverse Calculation Capability

Exact Euclidean remainder/quotient and modular inverse for signed integers; canonical Bézout coefficients satisfy the original-input identity.

Math Capability ID math.modulo version 1.1.2 CVP VERIFIED CURRENT Core

Model

Identity

Modes: remainder · inverse

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

SymbolQuantityUnitRole
a——input / output
modulus——input / output
review——output
api_version——output
api_contract_version——output
spec_version——output
pageCanonical calculator page URL—output
links——output

Trusted Math contract

Inspectable numeric contract for this Capability@Version. Not a rewrite of the engine.

FieldDeclaration
numeric_domaininteger
exactnessexact
algorithmBigInt Euclidean remainder / extended-Euclid modular inverse; canonical original-input Bézout coefficients
valid_domainSigned integer strings up to48 digits and512 characters, or safe JSON integers. Nonzero modulus; inverse |m|>=2 and gcd(a,m)=1. Matching aliases required; unknown keys and invalid types reject.
singularity_policyReject zero modulus, inverse modulus absolute value below2, and non-coprime inverse inputs with stable field-aware errors.
branch_policyremainder0<=r<|m|, q=(a-r)/m. Inverse canonicalx=inverse andy=(1-a*x)/m satisfy original a*x+m*y=1 for either sign.
tolerancenot applicable — exact integer identity
convergencenot applicable — non-iterative Euclidean / combinatorial
conditioningDiscrete integer changes can change remainder/invertibility abruptly. No floating rounding or measurement uncertainty model; not constant-time cryptography.
roundingnone — BigInt / exact integer
overflowcoded error or stringified BigInt when exceeding JSON number
reproducibilitydeterministic exact integer + Capability@Version
independent_oracleIndependent CPython integer division and pow modular inverse, full-pack/type/identity comparison in CVP math.modulo
golden_vectorsEvidence golden + boundary + property (and published_reference_case when listed)

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Example

One numerical check. The calculator page holds worked steps and FAQ.

a=-17 modulus=5 → remainder=3

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Core assurance · Sampled complete packs for both published modes, all signed branches and bounded48-digit cases. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP
CVP VERIFIED · CVP protocol 1.0.0-proposed · Core assurance · Sampled complete packs for both published modes, all signed branches and bounded48-digit cases· View Manifest · CVP overview · Specification
Verified scope
Sampled complete packs for both published modes, all signed branches and bounded48-digit cases
Assurance
Core
Declared partition coverage
PASS · 3/3 declared partitions (remainder, inverse, invalid-domain)
Calculation version
1.1.2
Verification
13/13 calculation tests · 3/3 legacy golden · 4/4 legacy boundary · 6/6 legacy property
Production surface contract
5/5
Versions
Calculation 1.1.2 · CVP protocol 1.0.0-proposed · Evidence 2026-10-28.meta-metrics-v2
Verification revision
2026-10-28.meta-metrics-v2 · 2/2 property · digest 7f68d65dd72b
Reference
O1 model · O2 expected_values · O2 numerical_behavior
Interfaces
PASS · UI (SSR) / REST / MCP
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.
CVP suite
92/92 golden · 5/5 CVP boundary · 8/8 invalid · 2/2 property · 2/2 metamorphic · 4/4 cross-interface · 1/1 cross-calculator · 5/5 CVP contract
Supplemental domain review
Not performed
Named expert review
Not performed
Version lock
Supported (409 VERSION_MISMATCH)
Artifact consistency
Build verified · 1.1.2 (workspace artifacts agree)
Review-policy tier
Engine tested — catalog token engine_tested; supplemental; not CVP status
This calculator CURRENT · Public schema 1.1.2 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 5/5.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/modulo' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"a":17,"modulus":5},"calculation_version":"1.1.2"}'

POST /api/v1/calc/modulo. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id
modulo
Engine
modulo
REST
POST /api/v1/calc/modulo
MCP
execute_calculation with capability_id: "math.modulo"
Agent input schema
Canonical (MCP / Agent)
REST input schema
Compatibility (tol[] / tol1…)
Output schema
JSON Schema (latest)
Versioned input schema
Immutable pin (1.1.2)
Versioned output schema
Immutable pin (1.1.2)

Operations

Declared calculation modes for this capability.

References

Human-readable sources plus CVP reference evidence classes.

Sources

Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect, then execute. Same engine as REST and the human calculator.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"math.modulo"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.1.2) when the result must stay reproducible.

Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.