{ "protocol": { "name": "CVP", "version": "1.0.0-proposed", "revision": "2026-09-13", "spec_sha256": "f62725968356c92930531cd6085db76e216da06e95be53d636b0d2cf3218b148", "spec": "https://www.calculatorx.com/developers/cvp/spec/1.0" }, "document_status": "proposed", "calculator": { "id": "gcf", "version": "1.0.3", "title": "GCF Calculator", "formula_family": "gcf", "capability_id": "math.gcf", "verification_revision": "2026-10-21.gcf-complete-contract-v4" }, "profile": "core", "status": "STALE", "verification_status": "VERIFIED", "production_freshness": "STALE", "overall_trust": "VERIFIED_STALE", "runner": { "name": "cvp-runner", "version": "1.0.0" }, "environment": { "runtime": "node", "runtime_version": "22.20.0", "numeric_model": "exact_integer", "os": "darwin" }, "suite": { "id": "gcf", "version": "1.0.3", "uri": "https://www.calculatorx.com/evidence/math.gcf/1.0.3.json", "verification_revision": "2026-10-21.gcf-complete-contract-v4" }, "obligation_set": [ "CVP-PROV-01", "CVP-MODEL-01", "CVP-SCOPE-01", "CVP-UNIT-01", "CVP-REF-01", "CVP-GOLD-01", "CVP-BND-01", "CVP-INV-01", "CVP-NUM-01", "CVP-COV-01", "CVP-CONTRACT-01", "CVP-DEP-01", "CVP-ART-01", "CVP-PROD-01", "CVP-PROP-01", "CVP-META-01", "CVP-XCAL-01", "CVP-IFACE-01" ], "provenance": { "mode": "direct", "sources": [ { "label": "Encyclopedia of Mathematics — Greatest common divisor", "kind": "other", "reference": "Definition; pairwise fold; prime-factor form", "url": "https://encyclopediaofmath.org/wiki/Greatest_common_divisor" }, { "label": "Encyclopedia of Mathematics — Euclidean algorithm", "kind": "other", "reference": "Remainder recurrence GCF(a,b)=GCF(b, a mod b)", "url": "https://encyclopediaofmath.org/wiki/Euclidean_algorithm" }, { "label": "CalculatorX integer convention", "kind": "other", "reference": "Absolute value; zero-set; 48-digit BigInt domain" }, { "label": "MIT Mathematics for Computer Science — Chapter 8: Number Theory", "kind": "other", "reference": "Chapter 8, including sections 8.2–8.9 and problem 8.24", "url": "https://ocw.mit.edu/courses/6-042j-mathematics-for-computer-science-spring-2015/mit6_042js15_textbook.pdf" } ] }, "controls": { "CVP-PROV-01": { "result": "PASS", "applicability": "required", "notes": "Sources present on evidence" }, "CVP-MODEL-01": { "result": "PASS", "applicability": "required", "notes": "GCF via Euclidean BigInt fold; O2 dual-checks binary (Stein) GCD; exact_integer / BigInt / exact_equality" }, "CVP-SCOPE-01": { "result": "PASS", "applicability": "required", "notes": "2–32 signed integers up to48 decimal digits; ignore zeros unless all zero; bounded work and complete output" }, "CVP-UNIT-01": { "result": "PASS", "applicability": "required", "notes": "dimensionless integer" }, "CVP-REF-01": { "result": "PASS", "applicability": "required", "notes": "O1 model + O2 expected_values/numerical_behavior (Euclidean dual-checked against binary GCD; exact_equality; same_runtime_as_iut)" }, "CVP-GOLD-01": { "result": "PASS", "applicability": "required", "notes": "6/6 legacy golden; 10/10 oracle-backed numeric" }, "CVP-BND-01": { "result": "PASS", "applicability": "required", "notes": "7/7 CVP boundary · 7/7 legacy Evidence boundary" }, "CVP-INV-01": { "result": "PASS", "applicability": "required", "notes": "5 invalid-domain cases" }, "CVP-NUM-01": { "result": "PASS", "applicability": "required", "notes": "exact_integer · BigInt · exact_equality (actual exact decimal string === independent oracle exact decimal string); mismatches=0; ULP not applicable" }, "CVP-COV-01": { "result": "PASS", "applicability": "required", "notes": "8/8 declared partitions (gcf, zero, negative, beyond-safe-integer, multi-input-fold, method-unavailable, xcal, invalid-domain) · 6 legacy golden / 7 CVP boundary unique cases · 5 Evidence invalid-input (may overlap boundary)" }, "CVP-CONTRACT-01": { "result": "PASS", "applicability": "required", "notes": "6/6 CVP contract · 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" }, "CVP-DEP-01": { "result": "PASS", "applicability": "required", "notes": "engine gcf; exact_integer BigInt (IUT/O2). Node is a runtime dependency, not the numeric model" }, "CVP-ART-01": { "result": "PASS", "applicability": "required", "notes": "release_integrity.status=verified · digests: artifact_evidence_sha256=Evidence core (Trust freshness) · cvp_evidence_digest=artifacts.evidence_digest (fingerprint v2) · evidence_bundle_sha256=legacy Evidence JSON bytes · evidence_catalog_digest=attested_catalog_sha256 · production_sha256=bound production report · see artifacts.digest_registry" }, "CVP-PROD-01": { "result": "PASS", "applicability": "required", "notes": "Capability production binding: STALE · Site report: stale · STALE (freshness / digest drift after last PASS snapshot) · site report stale · local checks pass · local production checks PASS; capability production binding is not CURRENT — final status must stay STALE, not VERIFIED · attestation_id=28e8435434ae51e54792530f2ecf4b9919e5516fa9bc11e57ba611be3b6b35be · Capability production binding: STALE · Site report: STALE · Public schema 1.0.3 observed · production binding STALE · Semantic contract ✓ · Last attestation PASS · Evidence changed after the last successful production attestation. Re-attestation required. · Public/cache ✓ · Origin ✓ · schema_const=1.0.3 · report output-const=pass · evidence-sha256=pass · semantic-contract=pass · capability-html-public-origin-agree=pass · cvp-manifest-public-origin-agree=pass · cvp-latest-alias-agrees=pass · cvp-immutable-manifest-fetch=pass · cvp-immutable-manifest-sha256=pass · cvp-latest-alias-matches-immutable=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=08644336c62608c231689a81851d856365919292294793bf800424200129ec8f · verified_at=2026-10-21T01:22:42.030Z · evidence_attested_at=2026-10-21T01:22:42.030Z · last_confirmed_current_at=2026-10-21T01:22:42.030Z · rendered_at=2026-10-21T01:22:42.030Z · binds=cvp_core_sha256 · Capability production binding: STALE · Site report: STALE · Evidence changed after the last successful production attestation. Re-attestation required.", "check_result": "PASS", "production_state": "STALE", "binding_current": false }, "CVP-DIM-01": { "result": "SKIP", "applicability": "not_applicable", "notes": "Unitless core calculator — no physical dimension algebra" }, "CVP-PROP-01": { "result": "PASS", "applicability": "applicable", "notes": "3/3 property" }, "CVP-META-01": { "result": "PASS", "applicability": "applicable", "notes": "1/1 metamorphic" }, "CVP-ROUND-01": { "result": "SKIP", "applicability": "not_applicable", "notes": "No inverse / round-trip vectors in pack — control not in obligation set" }, "CVP-XCAL-01": { "result": "PASS", "applicability": "applicable", "notes": "5/5 cross-calculator · xcal-lcm-8-12 PASS vs math.lcm; xcal-lcm-18-27 PASS vs math.lcm; xcal-lcm-coprime PASS vs math.lcm; xcal-lcm-neg PASS vs math.lcm; xcal-lcm-bigint-unsafe PASS vs math.lcm; xcal-lcm-all-zero-na N/A (GCF(a,b)·LCM(a,b)=|ab| is claimed for nonzero integers. GCF(0,0) is undefined, so the identity is not evaluated on the all-zero set.); xcal-fractions-na N/A (Fractions is listed as a related tool because it consumes GCF to reduce a/b. It does not encode GCF(a,b)·LCM(a,b)=|ab|.); xcal-factorial-na N/A (Factorial is listed as a related integer tool. It does not encode GCF(a,b)·LCM(a,b)=|ab|.); xcal-division-na N/A (Division is listed as a related tool. Euclidean remainder is used inside GCF, but the Division calculator does not encode GCF(a,b)·LCM(a,b)=|ab|.)" }, "CVP-IFACE-01": { "result": "PASS", "applicability": "applicable", "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). ui-ssr is query-result HTML, not a live browser session." }, "CVP-ORACLE-01": { "result": "SKIP", "applicability": "higher_assurance", "notes": "O2 present; O3 not required this wave" }, "CVP-EXP-01": { "result": "SKIP", "applicability": "optional", "notes": "named expert review not performed" } }, "interfaces": { "compared": [ "ui-ssr", "rest", "mcp" ], "result": "PASS", "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). ui-ssr is query-result HTML, not a live browser session." }, "artifacts": { "evidence_bundle_sha256": "9b31d1fd5fca6a2498c17e6dfdb8c634f34efa8a05ed45dca2c6d20fd1f757b8", "evidence_digest": "9af66f58265fbeebc60d298170d7d652bf6fad30183addcac1b7f39ce2e6b6d0", "production_sha256": "08644336c62608c231689a81851d856365919292294793bf800424200129ec8f", "attested_catalog_sha256": "ea3d150b6ba93a699d22c9af0b28bdb648537237c1123f70bb5225f72dbe7283", "production_checks": [ { "id": "math.gcf:output-const", "status": "pass", "detail": "output const 1.0.2 vs capability 1.0.2", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:evidence-sha256", "status": "pass", "detail": "b67af2483f41", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:semantic-contract", "status": "pass", "detail": "20/20", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:capability-html-public-origin-agree", "status": "pass", "detail": "public 1.0.2 vs origin 1.0.2", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:cvp-manifest-public-origin-agree", "status": "pass", "detail": "math.gcf/1.0.3/2026-10-21.gcf-complete-contract-v4/core/9af66f58265f", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z", "projection_compared": false }, { "id": "math.gcf:cvp-latest-alias-agrees", "status": "pass", "detail": "math.gcf/1.0.3/2026-10-21.gcf-complete-contract-v4/core/9af66f58265f", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z", "projection_compared": false }, { "id": "math.gcf:cvp-immutable-manifest-fetch", "status": "pass", "detail": "public=200 origin=200", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:cvp-immutable-manifest-sha256", "status": "pass", "detail": "2f7e2bf9bb70", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:cvp-latest-alias-matches-immutable", "status": "pass", "detail": "math.gcf/1.0.3/2026-10-21.gcf-complete-contract-v4/core/9af66f58265f", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z", "projection_compared": false }, { "id": "math.gcf:calculator-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" }, { "id": "math.gcf:evidence-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": false, "attestation_binding_current": false, "attested_at": "2026-10-21T01:22:42.030Z" } ], "digest_registry": { "digest_algorithm": "sha256", "canonicalization": "json-sorted-keys-utf8", "entries": [ { "name": "cvp_core_sha256", "field": "artifacts.cvp_core_sha256", "digest_scope": "cvp_verification_fingerprint_v2", "value": "9af66f58265fbeebc60d298170d7d652bf6fad30183addcac1b7f39ce2e6b6d0", "note": "Immutable verification core; excludes attestation/live-status and Evidence contract counts" }, { "name": "cvp_evidence_digest", "field": "artifacts.evidence_digest", "digest_scope": "cvp_verification_fingerprint_v2", "value": "9af66f58265fbeebc60d298170d7d652bf6fad30183addcac1b7f39ce2e6b6d0", "note": "Alias of cvp_core_sha256 (historical field name)" }, { "name": "artifact_evidence_sha256", "field": "release_integrity.digests.evidence_core_sha256", "digest_scope": "evidence_artifact_core", "value": "46b8671e022c013eaa3a462531bfe6bf8c8411b3d6dec05044731f5df00ab8b8", "note": "Published Evidence JSON core — Trust freshness / production bind subject" }, { "name": "evidence_catalog_digest", "field": "artifacts.attested_catalog_sha256", "digest_scope": "capability_catalog", "value": "ea3d150b6ba93a699d22c9af0b28bdb648537237c1123f70bb5225f72dbe7283", "note": "Capability catalog integrity; site-wide, not per-suite fingerprint" } ] }, "cvp_core_sha256": "9af66f58265fbeebc60d298170d7d652bf6fad30183addcac1b7f39ce2e6b6d0" }, "dependencies": [ { "name": "gcf-engine", "version": "1.0.3" }, { "name": "gcf-reference-oracle", "version": "1.0.0" }, { "name": "math.lcm", "version": "1.0.3", "role": "cross_calculator_peer", "capability_id": "math.lcm", "evidence_digest": "243e5df785916922d451ec831a8b81172dbde317d96fcd59206c30563574920a", "evidence": "https://www.calculatorx.com/evidence/math.lcm/1.0.3.cvp.json" }, { "name": "node", "version": "22.20.0" } ], "attestation": { "status": "STALE", "href": "/.well-known/calculatorx-production-attestation.json", "id": "28e8435434ae51e54792530f2ecf4b9919e5516fa9bc11e57ba611be3b6b35be", "attested_at": "2026-10-21T01:22:42.030Z", "last_confirmed_current_at": "2026-10-21T01:22:42.030Z", "site_attestation_current": false, "capability_attestation_current": false, "bound_snapshot_status": "pass", "live_report_status": "stale", "bound_attested_at": "2026-10-20T06:48:44.084Z", "live_updated_at": "2026-10-21T01:19:55.694Z", "bound_snapshot": { "status": "pass", "attested_at": "2026-10-20T06:48:44.084Z", "site_stale_count": 4 }, "live_site_status": { "href": "/.well-known/calculatorx-production-attestation.json" }, "bound_snapshot_site_stale_count": 4, "site_stale_capability_count": 4, "stale_reason": "Capability production binding: STALE · Site report: STALE · Evidence changed after the last successful production attestation. Re-attestation required.", "evidence_attested_at": "2026-10-21T01:22:42.030Z" }, "domain_review": { "status": "ABSENT", "spec_version": "1.0.3", "external_third_party": false, "note": "Named expert review not performed" }, "timestamps": { "verified_at": "2026-10-21T01:22:42.030Z", "generated_at": "2026-10-21T01:22:42.030Z", "rendered_at": "2026-10-21T01:22:42.030Z", "notes": "verified_at/generated_at mark the first publication of this cvp_core_sha256 (artifacts.evidence_digest alias) for suite verification. evidence_attested_at/attested_at is the first production bind of that core digest. last_confirmed_current_at is the latest site-wide report that still confirms CURRENT. rendered_at is this JSON serialization and is not part of cvp_core_sha256 / evidence_digest. Production attestation binds cvp_core_sha256 (binds evidence_digest). Causal order: verified_at ≤ evidence_attested_at ≤ last_confirmed_current_at. attestation.bound_snapshot.site_stale_count is the site-wide stale capability count at Manifest bind time — not a live value. Fetch attestation.live_site_status.href for the current site report." }, "tests": { "golden": { "passed": 10, "total": 10, "failed": 0 }, "boundary": { "passed": 7, "total": 7, "failed": 0 }, "invalid": { "passed": 5, "total": 5, "failed": 0 }, "property": { "passed": 3, "total": 3, "failed": 0 }, "round_trip": { "passed": 0, "total": 0, "failed": 0 }, "metamorphic": { "passed": 1, "total": 1, "failed": 0 }, "contract": { "passed": 6, "total": 6, "failed": 0 }, "cross_interface": { "passed": 2, "total": 2, "failed": 0 }, "cross_calculator": { "passed": 5, "total": 5, "failed": 0 } }, "numerical": { "representation": "exact_integer", "tolerance": { "type": "exact", "value": 0, "declared_before_evaluation": true, "rationale": "GCF is an exact integer. Acceptance is exact decimal-string identity vs an O2 module that dual-checks Euclidean fold against binary (Stein) GCD. Comparison is exact_equality; ULP is not applicable. Node/V8 is a runtime dependency, not the numeric model. Declared a priori." }, "profile": "exact_integer", "arithmetic": "BigInt", "comparison": "exact_equality", "criterion": "actual exact decimal string === independent oracle exact decimal string", "exact_policy": true, "ulp_applicable": false, "exact_mismatches": 0 }, "coverage": { "partitions": [ { "id": "gcf", "description": "GCF compute", "exercised": true, "case_count": 29 }, { "id": "zero", "description": "Zero in the input set", "exercised": true, "case_count": 4 }, { "id": "negative", "description": "Negative inputs (absolute-value convention)", "exercised": true, "case_count": 2 }, { "id": "beyond-safe-integer", "description": "Magnitude beyond Number.MAX_SAFE_INTEGER", "exercised": true, "case_count": 5 }, { "id": "multi-input-fold", "description": "Fold of three or more inputs", "exercised": true, "case_count": 8 }, { "id": "method-unavailable", "description": "Listing/prime/factor cross-check not available", "exercised": true, "case_count": 2 }, { "id": "xcal", "description": "Cross-calculator vs LCM: GCF(a,b)·LCM(a,b)=|ab| for nonzero integers", "exercised": true, "case_count": 5 }, { "id": "invalid-domain", "description": "Invalid inputs", "exercised": true, "case_count": 5 } ] }, "reference": { "items": [ { "class": "O1", "reference_scope": "model", "scope": "model", "label": "Greatest common factor (Euclidean)" }, { "class": "O2", "reference_scope": "expected_values", "scope": "expected_values", "label": "Separate-module gcf oracle — Euclidean BigInt fold dual-checked against binary (Stein) GCD (same runtime as IUT; not IUT transcription)", "engine": { "name": "gcf-reference", "numeric_model": "exact_integer", "criterion": "actual exact decimal string === independent oracle exact decimal string", "independent_of_iut": true, "same_runtime_as_iut": true } }, { "class": "O2", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O2 module backs exact decimal-string identity vs IUT — exact_equality, ULP not applicable", "engine": { "name": "gcf-reference", "numeric_model": "exact_integer", "criterion": "actual exact decimal string === independent oracle exact decimal string", "independent_of_iut": true, "same_runtime_as_iut": true } } ] }, "links": { "legacy_evidence": "https://www.calculatorx.com/evidence/math.gcf/1.0.3.json", "evidence_page": "https://www.calculatorx.com/evidence/math.gcf/1.0.3", "calculator": "https://www.calculatorx.com/calc/math/gcf", "schema": "https://www.calculatorx.com/developers/cvp/schema/cvp-evidence-1.0.json", "protocol": "https://www.calculatorx.com/developers/cvp/spec/1.0", "manifest": "https://www.calculatorx.com/evidence/math.gcf/1.0.3.cvp.json", "manifest_immutable": "https://www.calculatorx.com/evidence/math.gcf/1.0.3/2026-10-21.gcf-complete-contract-v4.cvp.json", "manifest_core": "https://www.calculatorx.com/evidence/math.gcf/1.0.3/2026-10-21.gcf-complete-contract-v4.9af66f58265f.cvp.json" }, "disclosure": { "policy": "calculatorx-public-evidence-v1", "full_validation": "private", "representation": "summary" } }