{
  "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": "plane-geometry",
    "version": "1.5.1",
    "title": "Plane Geometry Calculator",
    "formula_family": "plane-geometry",
    "capability_id": "math.geometry.plane",
    "verification_revision": "2026-10-28.metric-scope-v3"
  },
  "profile": "core",
  "verified_scope": "all published modes",
  "status": "VERIFIED",
  "verification_status": "VERIFIED",
  "production_freshness": "CURRENT",
  "overall_trust": "VERIFIED",
  "runner": {
    "name": "cvp-runner",
    "version": "1.0.0"
  },
  "environment": {
    "runtime": "node",
    "runtime_version": "22.20.0",
    "numeric_model": "IEEE-754 binary64",
    "os": "darwin"
  },
  "suite": {
    "id": "plane-geometry",
    "version": "1.5.1",
    "uri": "https://www.calculatorx.com/evidence/math.geometry.plane/1.5.1.json",
    "verification_revision": "2026-10-28.metric-scope-v3"
  },
  "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": "Mathematical symbols and notation. This standard is not numerical verification or an endorsement of this implementation.",
        "url": "https://www.iso.org/standard/64973.html"
      },
      {
        "label": "CRC Standard Mathematical Tables — plane polygons",
        "kind": "other",
        "reference": "Regular n-gon A = (n s²)/(4 tan(π/n)); parallelogram A = ab sin θ; shoelace / Meister–Gauss polygon area"
      },
      {
        "label": "Euclid’s Elements — I.35: Parallelograms on the Same Base",
        "kind": "other",
        "reference": "Equal-base, equal-height parallelograms have equal area. Comparing with a rectangle gives A = base × perpendicular height; side length is not generally the height. Mathematical reference only; not validation or endorsement of this implementation.",
        "url": "https://mathcs.clarku.edu/~djoyce/elements/bookI/propI35.html"
      },
      {
        "label": "Gilbert Strang, Calculus — Chapter 9: Polar Coordinates and Complex Numbers (MIT OpenCourseWare)",
        "kind": "other",
        "reference": "§§9.1–9.3 Polar Coordinates, Length and Area",
        "url": "https://ocw.mit.edu/courses/res-18-001-calculus-fall-2023/mitres_18_001_f17_ch09.pdf"
      },
      {
        "label": "Gilbert Strang, Calculus — Chapter 15: Vector Calculus (MIT OpenCourseWare)",
        "kind": "other",
        "reference": "§15.3 Green’s Theorem",
        "url": "https://ocw.mit.edu/courses/res-18-001-calculus-fall-2023/mitres_18_001_f17_ch15.pdf"
      },
      {
        "label": "Gilbert Strang, Calculus — Chapter 1: Introduction to Calculus (MIT OpenCourseWare)",
        "kind": "other",
        "reference": "§1.5 A Review of Trigonometry",
        "url": "https://ocw.mit.edu/courses/res-18-001-calculus-fall-2023/mitres_18_001_f17_ch01.pdf"
      }
    ]
  },
  "controls": {
    "CVP-PROV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Sources present on evidence"
    },
    "CVP-MODEL-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Rectangle, square, regular n-gon, annulus, parallelogram, isosceles trapezoid, irregular polygon (shoelace)."
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Seven Euclidean plane shapes; strict bounded decimals, normal binary64 positive measures, exact dyadic polygon area/topology, stable ring and angle formulas; complete secondary outputs. Simple3–8 vertex polygons and safe-integer regular n; no CAS."
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Consistent length; A in length², P in length"
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O2 expected_values + O2 numerical_behavior"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "9/9 legacy golden; 155/155 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "4/4 numeric-edge Evidence + 1/1 near-singularity numeric; illegal enum/system is Invalid only"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "5 Evidence illegal-input + 50/50 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "diagnostic_raw_leaf_ulp_max (not an acceptance budget)=3; policy declared a priori"
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "8/8 declared partitions (rectangle, square, regular-polygon, annulus, parallelogram, trapezoid, irregular-polygon, invalid-domain) · 9 legacy golden / 5 CVP boundary unique cases · 5 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 plane-geometry; 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": "this calculator CURRENT · bound snapshot pass @ 2026-10-29T01:22:37.788Z · live site-wide report stale @ 2026-10-29T01:23:59.828Z (52 other capabilities) · local checks pass · attestation_id=52c69c777f14b3653d6a0d99fffe81ea840d401226015698a80d3880c8382ade · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-10-29T01:22:37.788Z · Live production status STALE (52 capabilities; 324 remain CURRENT) @ 2026-10-29T01:23:59.828Z · Public schema 1.5.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.5.1 · 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=0904162d9842ae579e660eb678ec02f2ca6e852dd03b716905c0a6501acd7dae · verified_at=2026-10-28T16:33:53.880Z · evidence_attested_at=2026-10-28T16:33:53.880Z · last_confirmed_current_at=2026-10-29T01:22:37.788Z · rendered_at=2026-10-29T01:24:00.066Z · binds=cvp_core_sha256",
      "check_result": "PASS",
      "production_state": "CURRENT",
      "binding_current": true
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "Euclidean plane"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "4/4 property · enumerated fixed assertions (not generated; no seed)"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 metamorphic; domain=1; input-contract=1; limited to assessed relations/preconditions"
    },
    "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-rect-pythagorean PASS vs math.pythagorean; xcal-annulus-circles PASS vs math.geometry.circle"
    },
    "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": "47913aaa9464e88c81ea7f637b61c1d3e3b1361c311e4131082c464d1765f9f9",
    "evidence_digest": "0c354d2744d91d0efcd81adf4fd89300f487ee665e7a9b07a43816a13c30a550",
    "production_sha256": "0904162d9842ae579e660eb678ec02f2ca6e852dd03b716905c0a6501acd7dae",
    "attested_catalog_sha256": "163b0d7072a58bed20a0320572211167e1629730bef43c185b5f545ceac7744c",
    "production_checks": [
      {
        "id": "math.geometry.plane:output-const",
        "status": "pass",
        "detail": "output const 1.5.1 vs capability 1.5.1",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:evidence-sha256",
        "status": "pass",
        "detail": "6d787585f372",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:semantic-contract",
        "status": "pass",
        "detail": "25/25",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.5.1 vs origin 1.5.1",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.geometry.plane/1.5.1/2026-10-28.metric-scope-v3/core/0c354d2744d9",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z",
        "projection_compared": false
      },
      {
        "id": "math.geometry.plane:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "math.geometry.plane/1.5.1/2026-10-28.metric-scope-v3/core/0c354d2744d9",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z",
        "projection_compared": false
      },
      {
        "id": "math.geometry.plane:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "0c354d2744d9",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "math.geometry.plane/1.5.1/2026-10-28.metric-scope-v3/core/0c354d2744d9",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z",
        "projection_compared": false
      },
      {
        "id": "math.geometry.plane:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      },
      {
        "id": "math.geometry.plane:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-28T16:33:53.880Z"
      }
    ],
    "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": "0c354d2744d91d0efcd81adf4fd89300f487ee665e7a9b07a43816a13c30a550",
          "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": "0c354d2744d91d0efcd81adf4fd89300f487ee665e7a9b07a43816a13c30a550",
          "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": "6d787585f3726a1bb616fb7fc8bdf24a59485af90ba21c69fff37fc378ce127b",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "163b0d7072a58bed20a0320572211167e1629730bef43c185b5f545ceac7744c",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "0c354d2744d91d0efcd81adf4fd89300f487ee665e7a9b07a43816a13c30a550"
  },
  "dependencies": [
    {
      "name": "plane-geometry-engine",
      "version": "1.5.1"
    },
    {
      "name": "plane-geometry-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "math.pythagorean",
      "version": "1.1.6",
      "role": "cross_calculator_peer",
      "capability_id": "math.pythagorean",
      "evidence_digest": "4e661f033102d57e25604c76c92b099170b889cd33df23f00e2c46ec22307d0c",
      "evidence": "https://www.calculatorx.com/evidence/math.pythagorean/1.1.6.cvp.json"
    },
    {
      "name": "math.geometry.circle",
      "version": "1.1.2",
      "role": "cross_calculator_peer",
      "capability_id": "math.geometry.circle",
      "evidence_digest": "5d1d32fed335b23a9da1a913d4371429add16ecd3faa24e34b56fa7f07ad2d90",
      "evidence": "https://www.calculatorx.com/evidence/math.geometry.circle/1.1.2.cvp.json"
    },
    {
      "name": "node",
      "version": "22.20.0"
    }
  ],
  "attestation": {
    "status": "CURRENT",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "52c69c777f14b3653d6a0d99fffe81ea840d401226015698a80d3880c8382ade",
    "attested_at": "2026-10-28T16:33:53.880Z",
    "last_confirmed_current_at": "2026-10-29T01:22:37.788Z",
    "site_attestation_current": false,
    "capability_attestation_current": true,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-10-29T01:22:37.788Z",
    "live_updated_at": "2026-10-29T01:23:59.828Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-10-29T01:22:37.788Z",
      "site_stale_count": 52
    },
    "live_site_status": {
      "href": "/.well-known/calculatorx-production-attestation.json"
    },
    "bound_snapshot_site_stale_count": 52,
    "site_stale_capability_count": 52,
    "evidence_attested_at": "2026-10-28T16:33:53.880Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.5.1",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-10-28T16:33:53.880Z",
    "generated_at": "2026-10-28T16:33:53.880Z",
    "rendered_at": "2026-10-29T01:24:00.066Z",
    "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": 155,
      "total": 155,
      "failed": 0
    },
    "boundary": {
      "passed": 5,
      "total": 5,
      "failed": 0
    },
    "invalid": {
      "passed": 55,
      "total": 55,
      "failed": 0,
      "comparison": "exact_error_match"
    },
    "property": {
      "passed": 4,
      "total": 4,
      "failed": 0,
      "kind": "fixed"
    },
    "round_trip": {
      "passed": 0,
      "total": 0,
      "failed": 0
    },
    "metamorphic": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "contract": {
      "passed": 5,
      "total": 5,
      "failed": 0
    },
    "cross_interface": {
      "passed": 5,
      "total": 5,
      "failed": 0
    },
    "cross_calculator": {
      "passed": 2,
      "total": 2,
      "failed": 0
    }
  },
  "numerical": {
    "representation": "Normalized binary64; exact dyadic predicates/polynomial intermediates, binary64 trigonometry, finite normal positive outputs",
    "tolerance": {
      "type": "relative",
      "value": 1e-11,
      "rationale": "Independent mpmath750; exact branch/count/array cardinality and strict numeric types; no raw-input perturbation bound.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 3,
    "error_metric": "diagnostic_raw_leaf_ulp",
    "comparison_evidence_protocol": "scoped-comparison-v1",
    "max_error_observed_scope": "Raw finite matching numeric leaves across records/hops; diagnostic only. Acceptance is the per-record/hop comparison predicate and its declared scoped policy."
  },
  "coverage": {
    "partitions": [
      {
        "id": "rectangle",
        "description": "rectangle",
        "exercised": true,
        "case_count": 35
      },
      {
        "id": "square",
        "description": "square",
        "exercised": true,
        "case_count": 15
      },
      {
        "id": "regular-polygon",
        "description": "regular_polygon",
        "exercised": true,
        "case_count": 26
      },
      {
        "id": "annulus",
        "description": "annulus",
        "exercised": true,
        "case_count": 16
      },
      {
        "id": "parallelogram",
        "description": "parallelogram",
        "exercised": true,
        "case_count": 45
      },
      {
        "id": "trapezoid",
        "description": "trapezoid",
        "exercised": true,
        "case_count": 18
      },
      {
        "id": "irregular-polygon",
        "description": "irregular_polygon",
        "exercised": true,
        "case_count": 29
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 55
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
        "label": "Euclidean plane area and perimeter identities"
      },
      {
        "class": "O2",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Python mpmath750 Euclidean identities / exact-rational polygon fan reference",
        "engine": {}
      },
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