{
  "protocol": {
    "name": "CVP",
    "version": "1.0.0-proposed"
  },
  "document_status": "proposed",
  "calculator": {
    "id": "percentage",
    "version": "1.1.1",
    "title": "Percentage Calculator",
    "formula_family": "percentage",
    "capability_id": "math.percentage",
    "verification_revision": "2026-09-08.xcal"
  },
  "profile": "core",
  "status": "VERIFIED",
  "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": "percentage",
    "version": "1.1.1",
    "uri": "https://www.calculatorx.com/evidence/math.percentage/1.1.1.json",
    "verification_revision": "2026-09-08.xcal"
  },
  "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-ROUND-01",
    "CVP-XCAL-01",
    "CVP-IFACE-01"
  ],
  "provenance": {
    "mode": "direct",
    "sources": [
      {
        "label": "BIPM — The International System of Units (SI), 9th edition",
        "kind": "other",
        "reference": "Units accepted for use with the SI — percent (symbol %), 1% = 0.01",
        "url": "https://www.bipm.org/en/publications/si-brochure"
      },
      {
        "label": "NIST Special Publication 811 — Guide for the Use of the International System of Units (SI)",
        "kind": "other",
        "reference": "Writing values of quantities — the percent",
        "url": "https://www.nist.gov/pml/special-publication-811"
      },
      {
        "label": "CalculatorX percentage conventions",
        "kind": "other",
        "reference": "Six phrase modes, |old| percent change, non-negative percentage difference"
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
        "label": "Percent as 0.01 with phrase algebra"
      },
      {
        "class": "O2",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Separate-module percentage oracle — independent phrase algebra",
        "engine": {
          "name": "percentage-reference",
          "precision_bits": 53,
          "independent_of_iut": true
        }
      },
      {
        "class": "O2",
        "reference_scope": "numerical_behavior",
        "scope": "numerical_behavior",
        "label": "Same O2 module backs ≤2 ULP value comparison vs IUT",
        "engine": {
          "name": "percentage-reference",
          "precision_bits": 53,
          "independent_of_iut": true
        }
      }
    ],
    "notes": "Golden expected values use a separate O2 module (not IUT transcription). O2 shares Node/V8 binary64 with the IUT unless noted otherwise."
  },
  "controls": {
    "CVP-PROV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Sources present on evidence"
    },
    "CVP-MODEL-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Six percentage phrase modes"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "SI percent = 0.01; modes of / is-what / of-what / change / adjust-up / adjust-down / difference"
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "percent / 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": "12/12 legacy golden; 2/2 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "7/7 boundary"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "7 invalid-domain cases"
    },
    "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": "9/9 declared partitions (of, is-what, of-what, change, adjust-up, adjust-down, difference, invalid-domain, xcal) · 12 golden / 7 boundary unique cases · 7 Evidence invalid-input (may overlap boundary)"
    },
    "CVP-CONTRACT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "1/1 contract checks"
    },
    "CVP-DEP-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "engine percentage; Node binary64"
    },
    "CVP-ART-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "release_integrity.status=verified · evidence_digest=CVP verification fingerprint v2 (canonical inputs, expected/actual/status, policy, versions; independent of generated_at) · evidence_bundle_sha256=legacy Evidence JSON bytes · production_sha256=bound production attestation report"
    },
    "CVP-PROD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "CURRENT · site report pass · local checks pass · attestation_id=00c818a77ba026c2d6aa3f7402680cd2dac2a40a816209600bc3c3fcd0b8921c · CURRENT · Public schema 1.1.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.1.1 · report output-const=pass · evidence-sha256=pass · semantic-contract=pass · capability-html-public-origin-agree=pass · cvp-manifest-public-origin-agree=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=9424f31d3ca937ec4a453e41479201945df6495214f0a220ebb742e7fd1c3f20"
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "ratio×100"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 property"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 metamorphic"
    },
    "CVP-ROUND-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 round-trips"
    },
    "CVP-XCAL-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 cross-calculator · xcal-pc-40-50 PASS vs math.percent_change; xcal-pc-neg100-neg50 PASS vs math.percent_change; xcal-pc-old0 PASS vs math.percent_change; xcal-pe-na N/A (Percent error is listed as a related tool. It encodes |experimental−true|/|true|, not Δ%=100×(new−old)/|old|.); xcal-vat-na N/A (VAT is listed as a related finance tool. It does not encode the |old| percent-change identity used by Change mode.); xcal-fractions-na N/A (Fractions is listed as a related conversion tool. It does not encode Δ%=100×(new−old)/|old|.)"
    },
    "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": "expert_reviewed=false"
    }
  },
  "tests": {
    "golden": {
      "passed": 2,
      "total": 2,
      "failed": 0,
      "case_ids": [
        "g-of",
        "g-adjust-down"
      ]
    },
    "boundary": {
      "passed": 7,
      "total": 7,
      "failed": 0,
      "case_ids": [
        "diff-negative",
        "change-old-0",
        "is-what-y-0",
        "of-what-p-0",
        "diff-both-zero",
        "of-nan",
        "boundary-pct-diff-neg"
      ]
    },
    "invalid": {
      "passed": 7,
      "total": 7,
      "failed": 0,
      "case_ids": [
        "diff-negative",
        "change-old-0",
        "is-what-y-0",
        "of-what-p-0",
        "diff-both-zero",
        "of-nan",
        "boundary-pct-diff-neg"
      ]
    },
    "property": {
      "passed": 2,
      "total": 2,
      "failed": 0,
      "case_ids": [
        "prop-of-100",
        "prop-of-0"
      ],
      "definition_ids": [
        "hundred-percent",
        "zero-percent"
      ]
    },
    "round_trip": {
      "passed": 2,
      "total": 2,
      "failed": 0,
      "case_ids": [
        "rt-of-to-is-what",
        "rt-of-to-of-what"
      ]
    },
    "metamorphic": {
      "passed": 2,
      "total": 2,
      "failed": 0,
      "case_ids": [
        "meta-double-p",
        "meta-double-x"
      ],
      "definition_ids": [
        "scale-percent",
        "scale-base"
      ]
    },
    "contract": {
      "passed": 1,
      "total": 1,
      "failed": 0
    },
    "cross_interface": {
      "passed": 1,
      "total": 1,
      "failed": 0,
      "case_ids": [
        "iface-of"
      ]
    },
    "cross_calculator": {
      "passed": 3,
      "total": 3,
      "failed": 0,
      "case_ids": [
        "xcal-pc-40-50",
        "xcal-pc-neg100-neg50",
        "xcal-pc-old0"
      ]
    }
  },
  "coverage": {
    "partitions": [
      {
        "id": "of",
        "description": "What is P% of X",
        "exercised": true,
        "case_count": 13
      },
      {
        "id": "is-what",
        "description": "X is what % of Y",
        "exercised": true,
        "case_count": 2
      },
      {
        "id": "of-what",
        "description": "X is P% of what",
        "exercised": true,
        "case_count": 1
      },
      {
        "id": "change",
        "description": "Percent change old→new",
        "exercised": true,
        "case_count": 3
      },
      {
        "id": "adjust-up",
        "description": "Increase X by P%",
        "exercised": true,
        "case_count": 1
      },
      {
        "id": "adjust-down",
        "description": "Decrease X by P%",
        "exercised": true,
        "case_count": 2
      },
      {
        "id": "difference",
        "description": "Percent difference",
        "exercised": true,
        "case_count": 1
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 7
      },
      {
        "id": "xcal",
        "description": "Cross-calculator |old| percent change vs Percentage Change; Percent error / VAT / Fractions N/A",
        "exercised": true,
        "case_count": 3
      }
    ]
  },
  "numerical": {
    "representation": "IEEE-754 binary64 percent arithmetic",
    "tolerance": {
      "type": "ulp",
      "value": 2,
      "rationale": "Independent percent phrases vs IUT; ≤2 ULP on value. Declared a priori.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 0,
    "records": [
      {
        "id": "g-of",
        "reference": {
          "mode": "of",
          "value": 50
        },
        "actual": {
          "mode": "of",
          "mode_label": "P% of X",
          "heading": "20% of 250",
          "value": 50,
          "unit": null,
          "display": {
            "value": "50"
          },
          "explainer": "20% of 250 equals 50.",
          "inputs_summary": "P=20% · X=250",
          "formula": "Y = X × P / 100",
          "steps": [
            "What is 20% of 250?",
            "Y = 250 × 20 / 100",
            "= 50"
          ],
          "status": "success",
          "calculation_version": "1.1.1",
          "P": 20,
          "X": 250,
          "Y": 50
        },
        "error_ulp": 0,
        "threshold_ulp": 2
      },
      {
        "id": "g-adjust-down",
        "reference": {
          "mode": "adjust-down",
          "value": 450
        },
        "actual": {
          "mode": "adjust-down",
          "mode_label": "Decrease by %",
          "heading": "Decreased value",
          "value": 450,
          "unit": null,
          "display": {
            "value": "450"
          },
          "explainer": "500 decreased by 10% equals 450.",
          "inputs_summary": "X=500 · P=10%",
          "formula": "Y = X × (1 ± P/100)",
          "steps": [
            "500 decreased by 10%",
            "Y = 500 × (1 − 10/100)",
            "= 450"
          ],
          "status": "success",
          "calculation_version": "1.1.1",
          "X": 500,
          "P": 10,
          "Y": 450,
          "dir": "decrease"
        },
        "error_ulp": 0,
        "threshold_ulp": 2
      }
    ]
  },
  "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": "e32d992d968b6d77a0acd81bf268a95371e8fb4a5c2029d3c2c3d0d8a7e335cb",
    "evidence_digest": "e1b745d8821224141ebfee2bf2a4a250c5f4809eb79e8f583e8b1455e2cd9912",
    "production_sha256": "9424f31d3ca937ec4a453e41479201945df6495214f0a220ebb742e7fd1c3f20",
    "attested_catalog_sha256": "e03ef81b30568018b171fd1fc4757c2abe9df7220d9ff35bbaf08038d7630cdb",
    "production_checks": [
      {
        "id": "math.percentage:output-const",
        "status": "pass",
        "detail": "output const 1.1.1 vs capability 1.1.1",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      },
      {
        "id": "math.percentage:evidence-sha256",
        "status": "pass",
        "detail": "03d6504aac7e",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      },
      {
        "id": "math.percentage:semantic-contract",
        "status": "pass",
        "detail": "19/19",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      },
      {
        "id": "math.percentage:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.1.1 vs origin 1.1.1",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      },
      {
        "id": "math.percentage:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.percentage/1.1.1/2026-09-08.xcal/core/e1b745d88212",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z",
        "projection_compared": false,
        "observed_live_projection_at_attestation": "VERIFIED"
      },
      {
        "id": "math.percentage:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Manifest",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      },
      {
        "id": "math.percentage:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Manifest",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-10T02:52:51.379Z"
      }
    ]
  },
  "dependencies": [
    {
      "name": "percentage-engine",
      "version": "1.1.1"
    },
    {
      "name": "percentage-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "math.percent_change",
      "version": "1.1.0",
      "role": "cross_calculator_peer",
      "capability_id": "math.percent_change",
      "evidence_digest": "a7b9f7091c43c5bcbbe43d4be80b6d8bf8da4dc19f2e908b2b261cd959c5b968",
      "evidence": "https://www.calculatorx.com/evidence/math.percent_change/1.1.0.cvp.json"
    },
    {
      "name": "node",
      "version": "20.19.2"
    }
  ],
  "attestation": {
    "status": "CURRENT",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "00c818a77ba026c2d6aa3f7402680cd2dac2a40a816209600bc3c3fcd0b8921c",
    "attested_at": "2026-09-10T02:52:51.379Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.1.1"
  },
  "timestamps": {
    "verified_at": "2026-09-10T03:41:49.398Z",
    "generated_at": "2026-09-10T03:41:49.398Z"
  },
  "links": {
    "legacy_evidence": "https://www.calculatorx.com/evidence/math.percentage/1.1.1.json",
    "evidence_page": "https://www.calculatorx.com/evidence/math.percentage/1.1.1",
    "calculator": "https://www.calculatorx.com/calc/math/percentage",
    "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.percentage/1.1.1.cvp.json",
    "manifest_immutable": "https://www.calculatorx.com/evidence/math.percentage/1.1.1/2026-09-08.xcal.cvp.json"
  }
}