{
  "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": "linear-system",
    "version": "1.14.1",
    "title": "Linear System / Small Matrix Calculator",
    "formula_family": "linear_algebra",
    "capability_id": "math.linear_algebra",
    "verification_revision": "2026-10-07.solve-publication-diagnostics"
  },
  "profile": "core",
  "verified_scope": "all published modes",
  "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": "20.19.2",
    "numeric_model": "IEEE-754 binary64",
    "os": "darwin"
  },
  "suite": {
    "id": "linear-system",
    "version": "1.14.1",
    "uri": "https://www.calculatorx.com/evidence/math.linear_algebra/1.14.1.json",
    "verification_revision": "2026-10-07.solve-publication-diagnostics"
  },
  "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-DIM-01",
    "CVP-PROP-01",
    "CVP-META-01",
    "CVP-XCAL-01",
    "CVP-IFACE-01"
  ],
  "provenance": {
    "mode": "direct",
    "sources": [
      {
        "label": "ISO 80000-2:2019 Quantities and units — Mathematics",
        "kind": "standard",
        "reference": "Matrix, determinant, inverse, and rank notation for order 2–4"
      },
      {
        "label": "CRC / Strang — Ax=b, LU/QR/SVD, four fundamental subspaces",
        "kind": "other",
        "reference": "LU + partial pivoting solve; det; Gauss–Jordan inverse; rank-nullity; Householder QR; one-sided Jacobi SVD; RREF; κ₁(A)"
      }
    ]
  },
  "controls": {
    "CVP-PROV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Sources present on evidence"
    },
    "CVP-MODEL-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O2 Leibniz det, Cramer, cofactor inverse, minor-rank, Gram–Schmidt QR, column-wise Cholesky, closed-form 2×2/3×3 eigen vs IUT LU-solve / Householder / one-sided Jacobi SVD / Faddeev"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Order 2–4 square for solve/det/inverse/LU/Cholesky. qr, svd, and lstsq accept rectangular A with rows,cols ∈ [2,4]. Cholesky is SPD only (A = LLᵀ). Discovery pages lock one mode. Not a CAS, not Statistics regression, not large-matrix server compute."
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "dimensionless"
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O2 expected_values + O2 numerical_behavior"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "29/29 legacy golden; 26/26 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "5/5 numeric-edge Evidence + 3/3 near-singularity numeric; illegal enum/system is Invalid only"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "6 Evidence illegal-input + 8/8 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "max_error_observed_ulp=0; policy declared a priori"
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "19/19 declared partitions (solve, det, inverse, multiply, transpose, rank, eigen, lu, chol, qr, svd, lstsq, rref, condition, nullspace, columnspace, rowspace, leftnullspace, invalid-domain) · 29 legacy golden / 8 CVP boundary unique cases · 6 Evidence invalid-input (may overlap boundary)"
    },
    "CVP-CONTRACT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "5/5 CVP contract · release-artifacts-aligned=PASS · schema-output-required-declared=PASS · schema-valid-input-executes=PASS · engine-success-output-validates-schema=PASS · rest-success-payload-validates-schema=PASS"
    },
    "CVP-DEP-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "engine linear-algebra; Node binary64"
    },
    "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=b6db86a3946922a6529492107ca8043828115b3ffd21d9c4669ff69fb7f854ce · Capability production binding: STALE · Site report: STALE · Public schema 1.14.1 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=1.14.1 · 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=8a224dbdcd21223942d0e73df9a3c58e3b2c63d744bd5164790a86cc92da0fc9 · verified_at=2026-10-06T22:48:30.896Z · evidence_attested_at=2026-10-06T22:48:30.896Z · last_confirmed_current_at=2026-10-06T22:48:30.896Z · rendered_at=2026-10-06T22:48:30.896Z · 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": "PASS",
      "applicability": "applicable",
      "notes": "small real matrices"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "10/10 property · enumerated fixed assertions (not generated; no seed)"
    },
    "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": "2/2 cross-calculator · xcal-det-triple PASS vs math.vector; xcal-eigen-poly PASS vs math.polynomial.roots"
    },
    "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. 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-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. 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."
  },
  "artifacts": {
    "evidence_bundle_sha256": "10af22adc9d4a45b46ff55381dbe8c3070555fc1a5367cc9e5e1aadf7dc2c66d",
    "evidence_digest": "c6132667b855abd0feb0c8c825392fa0da5b61fb4972208aa0c0dbfc774bb951",
    "production_sha256": "8a224dbdcd21223942d0e73df9a3c58e3b2c63d744bd5164790a86cc92da0fc9",
    "attested_catalog_sha256": "6186d9f9c642e2b117ca4b72014d212f663656bb36624b7c12dbc67c29ee9f34",
    "production_checks": [
      {
        "id": "math.linear_algebra:output-const",
        "status": "pass",
        "detail": "output const 1.14.0 vs capability 1.14.0",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:evidence-sha256",
        "status": "pass",
        "detail": "a29b01988ee8",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:semantic-contract",
        "status": "pass",
        "detail": "58/58",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.14.0 vs origin 1.14.0",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.linear_algebra/1.14.1/2026-10-07.solve-publication-diagnostics/core/c6132667b855",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z",
        "projection_compared": false
      },
      {
        "id": "math.linear_algebra:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "math.linear_algebra/1.14.1/2026-10-07.solve-publication-diagnostics/core/c6132667b855",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z",
        "projection_compared": false
      },
      {
        "id": "math.linear_algebra:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "7307c47e0dc1",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "math.linear_algebra/1.14.1/2026-10-07.solve-publication-diagnostics/core/c6132667b855",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z",
        "projection_compared": false
      },
      {
        "id": "math.linear_algebra:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      },
      {
        "id": "math.linear_algebra:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-06T22:48:30.896Z"
      }
    ],
    "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": "c6132667b855abd0feb0c8c825392fa0da5b61fb4972208aa0c0dbfc774bb951",
          "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": "c6132667b855abd0feb0c8c825392fa0da5b61fb4972208aa0c0dbfc774bb951",
          "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": "94e2f742f4c2a1f4c437fa367c6c80cf9f631c659baf8f41a2b29b1dede15930",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "6186d9f9c642e2b117ca4b72014d212f663656bb36624b7c12dbc67c29ee9f34",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "c6132667b855abd0feb0c8c825392fa0da5b61fb4972208aa0c0dbfc774bb951"
  },
  "dependencies": [
    {
      "name": "linear-algebra-engine",
      "version": "1.14.1"
    },
    {
      "name": "linear-algebra-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "math.vector",
      "version": "1.6.1",
      "role": "cross_calculator_peer",
      "capability_id": "math.vector",
      "evidence_digest": "3e840b22dc12dce60edaa87d4f0b0749054aa01cbf39fc9ae4b70d1ab3c87bda",
      "evidence": "https://www.calculatorx.com/evidence/math.vector/1.6.1.cvp.json"
    },
    {
      "name": "math.polynomial.roots",
      "version": "1.2.1",
      "role": "cross_calculator_peer",
      "capability_id": "math.polynomial.roots",
      "evidence_digest": "6a2ac2cde6219237c0e85a901d560fefaef70e930e49552531a6bb084084cd81",
      "evidence": "https://www.calculatorx.com/evidence/math.polynomial.roots/1.2.1.cvp.json"
    },
    {
      "name": "node",
      "version": "20.19.2"
    }
  ],
  "attestation": {
    "status": "STALE",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "b6db86a3946922a6529492107ca8043828115b3ffd21d9c4669ff69fb7f854ce",
    "attested_at": "2026-10-06T22:48:30.896Z",
    "last_confirmed_current_at": "2026-10-06T22:48:30.896Z",
    "site_attestation_current": false,
    "capability_attestation_current": false,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-09-29T09:41:45.368Z",
    "live_updated_at": "2026-10-06T08:59:25.354Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-09-29T09:41:45.368Z",
      "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": "2026-10-06T22:48:30.896Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.14.1",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-10-06T22:48:30.896Z",
    "generated_at": "2026-10-06T22:48:30.896Z",
    "rendered_at": "2026-10-06T22:48:30.896Z",
    "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": 26,
      "total": 26,
      "failed": 0
    },
    "boundary": {
      "passed": 8,
      "total": 8,
      "failed": 0
    },
    "invalid": {
      "passed": 14,
      "total": 14,
      "failed": 0,
      "comparison": "exact_error_match"
    },
    "property": {
      "passed": 10,
      "total": 10,
      "failed": 0,
      "kind": "fixed"
    },
    "round_trip": {
      "passed": 0,
      "total": 0,
      "failed": 0
    },
    "metamorphic": {
      "passed": 1,
      "total": 1,
      "failed": 0
    },
    "contract": {
      "passed": 5,
      "total": 5,
      "failed": 0
    },
    "cross_interface": {
      "passed": 9,
      "total": 9,
      "failed": 0
    },
    "cross_calculator": {
      "passed": 2,
      "total": 2,
      "failed": 0
    }
  },
  "numerical": {
    "representation": "IEEE-754 binary64 small-matrix algebra; IUT publishes toPrecision(12) / roundSmart",
    "tolerance": {
      "type": "relative",
      "value": 1e-10,
      "rationale": "O2 uses Leibniz determinants, Cramer, cofactor inverse, minor-rank, Gram–Schmidt QR, column-wise Cholesky, and closed-form 2×2/3×3 eigen — not IUT Gaussian/Householder/Faddeev transcription. Relative 1e-10 covers presentation rounding; declared a priori.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 0
  },
  "coverage": {
    "partitions": [
      {
        "id": "solve",
        "description": "solve",
        "exercised": true,
        "case_count": 32
      },
      {
        "id": "det",
        "description": "det",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "inverse",
        "description": "inverse",
        "exercised": true,
        "case_count": 2
      },
      {
        "id": "multiply",
        "description": "multiply",
        "exercised": true,
        "case_count": 1
      },
      {
        "id": "transpose",
        "description": "transpose",
        "exercised": true,
        "case_count": 1
      },
      {
        "id": "rank",
        "description": "rank",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "eigen",
        "description": "eigen",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "lu",
        "description": "lu",
        "exercised": true,
        "case_count": 2
      },
      {
        "id": "chol",
        "description": "chol",
        "exercised": true,
        "case_count": 5
      },
      {
        "id": "qr",
        "description": "qr",
        "exercised": true,
        "case_count": 6
      },
      {
        "id": "svd",
        "description": "svd",
        "exercised": true,
        "case_count": 7
      },
      {
        "id": "lstsq",
        "description": "lstsq",
        "exercised": true,
        "case_count": 8
      },
      {
        "id": "rref",
        "description": "rref",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "condition",
        "description": "condition",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "nullspace",
        "description": "nullspace",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "columnspace",
        "description": "columnspace",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "rowspace",
        "description": "rowspace",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "leftnullspace",
        "description": "leftnullspace",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 14
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
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