Home Developers Capabilities Integer sequences

CVP verified calculation capability

Integer sequences Calculation Capability

Arithmetic and geometric sequences, Fibonacci (F_0=0), and linear recurrences. Exact BigInt. Discovery pages share this capability. Not Pascal, not partition, not n!. Engine id is sequence — never arithmetic.

Math Capability ID math.sequences version 1.0.3 CVP VERIFIED CURRENT Core

Model

Arithmetic

Inputs / Outputs

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

SymbolQuantityUnitRole
n——input / output
nInput——input / output
a——input / output
first——input / output
a1——input / output
aInput——input / output
d——input
difference——input
common_difference——input
dInput——input
r——input
ratio——input
common_ratio——input
rInput——input
p——input
pInput——input
q——input
qInput——input
a0——input
u0——input
a0Input——input
u1——input
a1Input——input
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 AP/GP closed forms; iterative Fibonacci and second-order recurrence
valid_domainAP/GP n1..1000,Fibonacci/recurrence n0..1000; signed integer coefficients<=48digits, rawtokens<=512chars,index<=4digits; strict agreeing aliases andactive fields
singularity_policyReject invalid/missing/unknown/conflicting/inactive inputs; no approximate arithmetic. Safe JSON integers or exactdecimalstrings; explicit graph omission outside safe coordinates.
branch_policynot applicable — integer domain
tolerancenot applicable — exact integer identity
convergencenot applicable — non-iterative Euclidean / combinatorial
conditioningnot applicable — not a floating matrix
roundingnone — BigInt / exact integer
overflowcoded error or stringified BigInt when exceeding JSON number
reproducibilitydeterministic exact integer + Capability@Version
independent_oracle37 independent CPython integer enumeration/matrix-power complete packs; exact complete keys/types/values/metadata; old1.0.1 pins retained
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.

mode=arithmetic a=2 d=3 n=5 → 14

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Core assurance · four integer sequence modes andfour entries. 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 · four integer sequence modes andfour entries· View Manifest · CVP overview · Specification
Verified scope
four integer sequence modes andfour entries
Assurance
Core
Declared partition coverage
PASS · 5/5 declared partitions (arithmetic, geometric, fibonacci, linear_recurrence, invalid)
Calculation version
1.0.3
Verification
12/12 calculation tests · 4/4 legacy golden · 2/2 legacy boundary · 6/6 legacy property
Production surface contract
6/6
Versions
Calculation 1.0.3 · 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 862921453e34
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 29/29 (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
37/37 golden · 1/1 CVP boundary · 31/31 invalid · 2/2 property · 2/2 metamorphic · 69/69 cross-interface · 1/1 cross-calculator · 6/6 CVP contract
Supplemental domain review
Not performed
Named expert review
Not performed
Version lock
Supported (409 VERSION_MISMATCH)
Artifact consistency
Build verified · 1.0.3 (workspace artifacts agree)
Review-policy tier
Engine tested — catalog token engine_tested; supplemental; not CVP status
This calculator CURRENT · Public schema 1.0.3 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 6/6.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/sequence' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"mode":"arithmetic","a":2,"d":3,"n":5},"calculation_version":"1.0.3"}'

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

Full REST contract: REST API docs.

Tool id
sequence
Engine
sequence
REST
POST /api/v1/calc/sequence
MCP
execute_calculation with capability_id: "math.sequences"
Agent input schema
Canonical (MCP / Agent)
Output schema
JSON Schema (latest)
Versioned input schema
Immutable pin (1.0.3)
Versioned output schema
Immutable pin (1.0.3)

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.sequences"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.0.3) when the result must stay reproducible.

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