{
  "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": "type-b-nu",
    "version": "1.0.0",
    "title": "Type B Degrees of Freedom Calculator",
    "formula_family": "type-b-nu",
    "capability_id": "engineering.uncertainty.type_b_nu",
    "verification_revision": "2026-09-16.o2-o3"
  },
  "profile": "engineering",
  "verified_scope": "GUM G.4.2 Type B degrees of freedom ν = ½(u/σ(u))², including σ(u)=0 → infinite, + O3 mpmath tabulated ν.",
  "deferred_scope": "Not Type B u_B from a half-width, not Welch ν_eff, not U = k·u_c, and not trapezoidal Type B.",
  "status": "VERIFIED",
  "verification_status": "VERIFIED",
  "production_freshness": "CURRENT",
  "overall_trust": "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": "type-b-nu",
    "version": "1.0.0",
    "uri": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/1.0.0.json",
    "verification_revision": "2026-09-16.o2-o3"
  },
  "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-IFACE-01"
  ],
  "provenance": {
    "mode": "direct",
    "sources": [
      {
        "label": "JCGM 100:2008 — Evaluation of measurement data (GUM)",
        "kind": "standard",
        "reference": "G.4.2 Degrees of freedom of a Type B evaluation",
        "url": "https://www.bipm.org/en/committees/jc/jcgm/publications"
      },
      {
        "label": "JCGM 100:2008 — Evaluation of measurement data (GUM)",
        "kind": "standard",
        "reference": "G.4.2 (example) 25% relative uncertainty",
        "url": "https://www.bipm.org/utils/common/pdf/jcgm/JCGM_100_2008_E.pdf"
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
        "label": "GUM G.4.2 Type B degrees of freedom"
      },
      {
        "class": "O3",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Precomputed mpmath high-precision G.4.2 ν (80 dps) rounded to nearest binary64 — not V8 hypot",
        "engine": {
          "name": "type-b-nu-mpmath-o3",
          "precision_bits": 265,
          "independent_of_iut": true,
          "same_runtime_as_iut": false,
          "library": "mpmath 1.4.1",
          "mpmath_dps": 80,
          "generator_version": "1.0.0",
          "generator_sha256": "22045c453cab09f2f9ead5cf4a487b9d6ec06bba64a740def78bb76651658592",
          "table_sha256": "5df02b81ce3ba86dff9a8c8250667e83c67340870bd77a6a28eddfc632cfda7a",
          "seed": "20260916.type-b-nu-o3",
          "source": "https://www.calculatorx.com/developers/cvp/reproduce/type-b-nu-o3-tables.json",
          "public_table": "/developers/cvp/reproduce/type-b-nu-o3-tables.json",
          "public_generator": "/developers/cvp/reproduce/generate-type-b-nu-o3.py"
        }
      },
      {
        "class": "O3",
        "reference_scope": "numerical_behavior",
        "scope": "numerical_behavior",
        "label": "Same O3 table vs IUT ν; ≤2 ULP on tabulated vectors only",
        "engine": {
          "name": "type-b-nu-mpmath-o3",
          "precision_bits": 265,
          "independent_of_iut": true,
          "same_runtime_as_iut": false,
          "library": "mpmath 1.4.1",
          "mpmath_dps": 80,
          "generator_version": "1.0.0",
          "generator_sha256": "22045c453cab09f2f9ead5cf4a487b9d6ec06bba64a740def78bb76651658592",
          "table_sha256": "5df02b81ce3ba86dff9a8c8250667e83c67340870bd77a6a28eddfc632cfda7a",
          "seed": "20260916.type-b-nu-o3",
          "source": "https://www.calculatorx.com/developers/cvp/reproduce/type-b-nu-o3-tables.json",
          "public_table": "/developers/cvp/reproduce/type-b-nu-o3-tables.json",
          "public_generator": "/developers/cvp/reproduce/generate-type-b-nu-o3.py"
        }
      },
      {
        "class": "O2",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Separate-module GUM G.4.2 Type B ν oracle — same V8 binary64 as IUT",
        "engine": {
          "name": "type-b-nu-reference",
          "precision_bits": 53,
          "independent_of_iut": true
        }
      },
      {
        "class": "O2",
        "reference_scope": "numerical_behavior",
        "scope": "numerical_behavior",
        "label": "Same O2 module backs ≤2 ULP ν comparison vs IUT",
        "engine": {
          "name": "type-b-nu-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": "GUM G.4.2 ν=½(u/σ(u))²; O3 tabulated ν"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "One Type B ν_i. Not Welch, not U=k·u_c. O3 tabulated vectors only."
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "u and σ(u) share an implied unit. ν is dimensionless."
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O2 expected_values + O2 numerical_behavior + O3 tabulated G.4.2"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "1/1 legacy golden; 5/5 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "4/4 CVP boundary · 4/4 legacy Evidence boundary"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "3 Evidence illegal-input + 4/4 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "max_error_observed_ulp=1; policy declared a priori"
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "5/5 partitions (textbook-25, infinite, other-finite, alias, invalid-domain)"
    },
    "CVP-CONTRACT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "4/4 CVP contract"
    },
    "CVP-DEP-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "engine type-b-nu; 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 @ 2026-09-16T23:18:54.751Z · live site-wide report stale @ 2026-09-16T23:18:57.583Z (4 other capabilities) · local checks pass · attestation_id=bf3fe5ab59e4bbc9e50f340c6c537d3cf046a9b32473980b03131666eea4e751 · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-09-16T23:18:54.751Z · Live production status STALE (4 capabilities; 160 remain CURRENT) @ 2026-09-16T23:18:57.583Z · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.0.0 · 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 · cvp-reproduce-manifest-agree=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=58fe84b53a8948a8ed33bf1d0f10c2dc305d423b0415cb204b41bee40e09d0f5 · verified_at=2026-09-16T05:18:43.917Z · evidence_attested_at=2026-09-16T05:18:43.917Z · last_confirmed_current_at=2026-09-16T23:18:54.751Z · rendered_at=2026-09-16T23:18:57.678Z · binds=cvp_core_sha256",
      "check_result": "PASS",
      "production_state": "CURRENT",
      "binding_current": true
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "Type B degrees of freedom"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 property · enumerated fixed assertions (not generated; no seed)"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 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": "SKIP",
      "applicability": "not_applicable",
      "notes": "No related calculator in the same formula family / no related-identity peers declared — control not in obligation set"
    },
    "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": "PASS",
      "applicability": "higher_assurance",
      "notes": "O3 8/8 tabulated vectors vs IUT · O2: GUM G.4.2 ν = ½(u/σ(u))² vs separate-module identities (≤2 ULP). Not Type B u_B, not Welch ν_eff, not U=k·u_c. ≤2 ULP vs O3 applies only to the published tabulated G.4.2 vectors (GUM 25%, infinite, 10%, aliases, scale, σ(u)/u=0.5). It is not a whole-domain guarantee and does not cover Welch ν_eff or U=k·u_c."
    },
    "CVP-EXP-01": {
      "result": "SKIP",
      "applicability": "optional",
      "notes": "named expert review not performed"
    }
  },
  "tests": {
    "golden": {
      "passed": 5,
      "total": 5,
      "failed": 0,
      "case_ids": [
        "g-gum25",
        "g-inf",
        "g-10pct",
        "g-alias",
        "g-scale"
      ]
    },
    "boundary": {
      "passed": 4,
      "total": 4,
      "failed": 0,
      "case_ids": [
        "boundary-tbnu-inf",
        "boundary-tbnu-missing",
        "boundary-tbnu-u",
        "boundary-tbnu-neg"
      ]
    },
    "invalid": {
      "passed": 7,
      "total": 7,
      "failed": 0,
      "case_ids": [
        "boundary-tbnu-missing",
        "boundary-tbnu-u",
        "boundary-tbnu-neg",
        "inv-missing",
        "inv-u",
        "inv-neg",
        "inv-missing-u"
      ],
      "comparison": "exact_error_match",
      "records": [
        {
          "id": "inv-missing",
          "comparison": "exact_error_match",
          "expected": {
            "code": "MISSING_REQUIRED_INPUT"
          },
          "actual": {
            "code": "MISSING_REQUIRED_INPUT"
          },
          "match": true
        },
        {
          "id": "inv-u",
          "comparison": "exact_error_match",
          "expected": {
            "code": "VALUE_MUST_BE_POSITIVE"
          },
          "actual": {
            "code": "VALUE_MUST_BE_POSITIVE"
          },
          "match": true
        },
        {
          "id": "inv-neg",
          "comparison": "exact_error_match",
          "expected": {
            "code": "VALUE_OUT_OF_RANGE"
          },
          "actual": {
            "code": "VALUE_OUT_OF_RANGE"
          },
          "match": true
        },
        {
          "id": "inv-missing-u",
          "comparison": "exact_error_match",
          "expected": {
            "code": "MISSING_REQUIRED_INPUT"
          },
          "actual": {
            "code": "MISSING_REQUIRED_INPUT"
          },
          "match": true
        }
      ]
    },
    "property": {
      "passed": 3,
      "total": 3,
      "failed": 0,
      "case_ids": [
        "prop-gum25",
        "prop-inf",
        "prop-alias"
      ],
      "kind": "fixed",
      "claim_scope": "Enumerated identities: u=2 σ(u)=0.5 → ν=8; σ(u)=0 → infinite. Not generated property tests.",
      "definition_ids": [
        "gum-g42-25-percent",
        "sigma-u-zero-infinite",
        "u-b-su-aliases"
      ]
    },
    "round_trip": {
      "passed": 0,
      "total": 0,
      "failed": 0,
      "case_ids": []
    },
    "metamorphic": {
      "passed": 2,
      "total": 2,
      "failed": 0,
      "case_ids": [
        "meta-scale",
        "meta-rel"
      ],
      "definition_ids": [
        "homogeneous-scale-invariant-nu",
        "rel-halves-nu-times-four"
      ]
    },
    "contract": {
      "passed": 4,
      "total": 4,
      "failed": 0
    },
    "cross_interface": {
      "passed": 4,
      "total": 4,
      "failed": 0,
      "case_ids": [
        "iface-gum25",
        "iface-inf",
        "iface-10pct",
        "iface-invalid-u"
      ]
    },
    "o3": {
      "passed": 8,
      "total": 8,
      "failed": 0,
      "case_ids": [
        "o3-gum25",
        "o3-inf",
        "o3-10pct",
        "o3-alias",
        "o3-scale",
        "o3-half",
        "o3-ui",
        "o3-tight"
      ],
      "generator_id": "type-b-nu-mpmath-o3",
      "seed": "20260916.type-b-nu-o3",
      "table_sha256": "5df02b81ce3ba86dff9a8c8250667e83c67340870bd77a6a28eddfc632cfda7a",
      "max_error_ulp": 1,
      "reproduce": "python3 generate-type-b-nu-o3.py",
      "table_url": "/developers/cvp/reproduce/type-b-nu-o3-tables.json",
      "generator_url": "/developers/cvp/reproduce/generate-type-b-nu-o3.py",
      "claim_scope": "O2: GUM G.4.2 ν = ½(u/σ(u))² vs separate-module identities (≤2 ULP). Not Type B u_B, not Welch ν_eff, not U=k·u_c. ≤2 ULP vs O3 applies only to the published tabulated G.4.2 vectors (GUM 25%, infinite, 10%, aliases, scale, σ(u)/u=0.5). It is not a whole-domain guarantee and does not cover Welch ν_eff or U=k·u_c.",
      "reproduce_url": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/reproduce"
    }
  },
  "coverage": {
    "partitions": [
      {
        "id": "textbook-25",
        "description": "GUM G.4.2 25% textbook case (rel=0.25, not alias)",
        "exercised": true,
        "case_count": 8
      },
      {
        "id": "infinite",
        "description": "σ(u)=0 → ν infinite",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "other-finite",
        "description": "Finite ν, rel ≠ 0.25",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "alias",
        "description": "u_B / u_i / su / delta_u aliases",
        "exercised": true,
        "case_count": 4
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 7
      }
    ]
  },
  "numerical": {
    "representation": "IEEE-754 binary64",
    "claim_scope": "O2: GUM G.4.2 ν = ½(u/σ(u))² vs separate-module identities (≤2 ULP). Not Type B u_B, not Welch ν_eff, not U=k·u_c. ≤2 ULP vs O3 applies only to the published tabulated G.4.2 vectors (GUM 25%, infinite, 10%, aliases, scale, σ(u)/u=0.5). It is not a whole-domain guarantee and does not cover Welch ν_eff or U=k·u_c.",
    "tolerance": {
      "type": "ulp",
      "value": 2,
      "rationale": "Independent Type B ν identities vs IUT on same V8 binary64. ≤2 ULP declared a priori.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 1,
    "records": [
      {
        "id": "g-gum25",
        "reference": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "golden"
      },
      {
        "id": "g-inf",
        "reference": {
          "nu": null,
          "rel": 0,
          "u": 1,
          "sigma_u": 0,
          "infinite": true
        },
        "actual": {
          "nu": null,
          "rel": 0,
          "u": 1,
          "sigma_u": 0,
          "infinite": true
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "infinite": {
            "ok": true,
            "error_ulp": 0
          },
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "golden"
      },
      {
        "id": "g-10pct",
        "reference": {
          "nu": 49.99999999999999,
          "rel": 0.1,
          "u": 1,
          "sigma_u": 0.1,
          "infinite": false
        },
        "actual": {
          "nu": 49.99999999999999,
          "rel": 0.1,
          "u": 1,
          "sigma_u": 0.1,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "golden"
      },
      {
        "id": "g-alias",
        "reference": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "golden"
      },
      {
        "id": "g-scale",
        "reference": {
          "nu": 8,
          "rel": 0.25,
          "u": 4,
          "sigma_u": 1,
          "infinite": false
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 4,
          "sigma_u": 1,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "golden"
      },
      {
        "id": "meta-scale",
        "reference": 1,
        "actual": 1,
        "error_ulp": 0,
        "threshold_ulp": 2,
        "suite": "metamorphic",
        "hops": {
          "base": {
            "reference": {
              "nu": 8,
              "rel": 0.25,
              "u": 2,
              "sigma_u": 0.5,
              "infinite": false
            },
            "actual": {
              "nu": 8,
              "rel": 0.25,
              "u": 2,
              "sigma_u": 0.5,
              "infinite": false
            },
            "error_ulp": 0
          },
          "follow": {
            "reference": {
              "nu": 8,
              "rel": 0.25,
              "u": 4,
              "sigma_u": 1,
              "infinite": false
            },
            "actual": {
              "nu": 8,
              "rel": 0.25,
              "u": 4,
              "sigma_u": 1,
              "infinite": false
            },
            "error_ulp": 0
          },
          "relation": {
            "reference": 1,
            "actual": 1,
            "error_ulp": 0
          }
        }
      },
      {
        "id": "meta-rel",
        "reference": 4,
        "actual": 4,
        "error_ulp": 0,
        "threshold_ulp": 2,
        "suite": "metamorphic",
        "hops": {
          "base": {
            "reference": {
              "nu": 8,
              "rel": 0.25,
              "u": 2,
              "sigma_u": 0.5,
              "infinite": false
            },
            "actual": {
              "nu": 8,
              "rel": 0.25,
              "u": 2,
              "sigma_u": 0.5,
              "infinite": false
            },
            "error_ulp": 0
          },
          "follow": {
            "reference": {
              "nu": 32,
              "rel": 0.125,
              "u": 2,
              "sigma_u": 0.25,
              "infinite": false
            },
            "actual": {
              "nu": 32,
              "rel": 0.125,
              "u": 2,
              "sigma_u": 0.25,
              "infinite": false
            },
            "error_ulp": 0
          },
          "relation": {
            "reference": 4,
            "actual": 4,
            "error_ulp": 0
          }
        }
      },
      {
        "id": "o3-gum25",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 8,
          "rel": 0.25
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-inf",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": true,
          "nu": null,
          "rel": 0
        },
        "actual": {
          "nu": null,
          "rel": 0,
          "u": 1,
          "sigma_u": 0,
          "infinite": true
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "infinite": {
            "ok": true,
            "error_ulp": 0
          },
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-10pct",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 50,
          "rel": 0.1
        },
        "actual": {
          "nu": 49.99999999999999,
          "rel": 0.1,
          "u": 1,
          "sigma_u": 0.1,
          "infinite": false
        },
        "error_ulp": 1,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 1
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-alias",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 8,
          "rel": 0.25
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-scale",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 8,
          "rel": 0.25
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 4,
          "sigma_u": 1,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-half",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 2,
          "rel": 0.5
        },
        "actual": {
          "nu": 2,
          "rel": 0.5,
          "u": 2,
          "sigma_u": 1,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-ui",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 8,
          "rel": 0.25
        },
        "actual": {
          "nu": 8,
          "rel": 0.25,
          "u": 2,
          "sigma_u": 0.5,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      },
      {
        "id": "o3-tight",
        "reference": {
          "oracle_layer": "analytic",
          "infinite": false,
          "nu": 20000,
          "rel": 0.005
        },
        "actual": {
          "nu": 20000,
          "rel": 0.005,
          "u": 10,
          "sigma_u": 0.05,
          "infinite": false
        },
        "error_ulp": 0,
        "threshold_ulp": 2,
        "fields": {
          "nu": {
            "ok": true,
            "error_ulp": 0
          },
          "rel": {
            "ok": true,
            "error_ulp": 0
          }
        },
        "suite": "o3"
      }
    ]
  },
  "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": "0a11f2addd4cc477fa05c36eb0efb0f18ac695e2af39d88a64a8bfa3c129443a",
    "evidence_digest": "0834186914287ec8311b9c28b69633bc9963aefe4d201985c8feed3a9ae80d86",
    "production_sha256": "58fe84b53a8948a8ed33bf1d0f10c2dc305d423b0415cb204b41bee40e09d0f5",
    "attested_catalog_sha256": "006a786d7fd29244ed7da1c582af2a6072358ff25a2e07cbc8909b3ae65fb0af",
    "production_checks": [
      {
        "id": "engineering.uncertainty.type_b_nu:output-const",
        "status": "pass",
        "detail": "output const 1.0.0 vs capability 1.0.0",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:evidence-sha256",
        "status": "pass",
        "detail": "7fd3ddfb174e",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:semantic-contract",
        "status": "pass",
        "detail": "8/8",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.0.0 vs origin 1.0.0",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "engineering.uncertainty.type_b_nu/1.0.0/2026-09-16.o2-o3/engineering/083418691428",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z",
        "projection_compared": false
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "engineering.uncertainty.type_b_nu/1.0.0/2026-09-16.o2-o3/engineering/083418691428",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z",
        "projection_compared": false
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "083418691428",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "engineering.uncertainty.type_b_nu/1.0.0/2026-09-16.o2-o3/engineering/083418691428",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z",
        "projection_compared": false
      },
      {
        "id": "engineering.uncertainty.type_b_nu:cvp-reproduce-manifest-agree",
        "status": "pass",
        "detail": "2026-09-16.o2-o3 · 5df02b81ce3b",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      },
      {
        "id": "engineering.uncertainty.type_b_nu:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-09-16T05:18:43.917Z"
      }
    ],
    "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": "0834186914287ec8311b9c28b69633bc9963aefe4d201985c8feed3a9ae80d86",
          "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": "0834186914287ec8311b9c28b69633bc9963aefe4d201985c8feed3a9ae80d86",
          "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": "7fd3ddfb174e402ba73d2509563e11b0faea37fcefd66e0c0e596cb3d57808ab",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "006a786d7fd29244ed7da1c582af2a6072358ff25a2e07cbc8909b3ae65fb0af",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "0834186914287ec8311b9c28b69633bc9963aefe4d201985c8feed3a9ae80d86"
  },
  "dependencies": [
    {
      "name": "type-b-nu-engine",
      "version": "1.0.0"
    },
    {
      "name": "type-b-nu-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "type-b-nu-mpmath-o3-table",
      "version": "type-b-nu-mpmath-o3"
    },
    {
      "name": "node",
      "version": "20.19.2"
    }
  ],
  "attestation": {
    "status": "CURRENT",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "bf3fe5ab59e4bbc9e50f340c6c537d3cf046a9b32473980b03131666eea4e751",
    "attested_at": "2026-09-16T05:18:43.917Z",
    "last_confirmed_current_at": "2026-09-16T23:18:54.751Z",
    "site_attestation_current": false,
    "capability_attestation_current": true,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-09-16T23:18:54.751Z",
    "live_updated_at": "2026-09-16T23:18:57.583Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-09-16T23:18:54.751Z",
      "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,
    "evidence_attested_at": "2026-09-16T05:18:43.917Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.0.0",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-09-16T05:18:43.917Z",
    "generated_at": "2026-09-16T05:18:43.917Z",
    "rendered_at": "2026-09-16T23:18:57.678Z",
    "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."
  },
  "links": {
    "legacy_evidence": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/1.0.0.json",
    "evidence_page": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/1.0.0",
    "calculator": "https://www.calculatorx.com/calc/engineering/type-b-degrees-of-freedom",
    "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/engineering.uncertainty.type_b_nu/1.0.0.cvp.json",
    "manifest_immutable": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/1.0.0/2026-09-16.o2-o3.cvp.json",
    "reproduce": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/reproduce",
    "o3_table": "https://www.calculatorx.com/developers/cvp/reproduce/type-b-nu-o3-tables.json",
    "o3_generator": "https://www.calculatorx.com/developers/cvp/reproduce/generate-type-b-nu-o3.py",
    "manifest_core": "https://www.calculatorx.com/evidence/engineering.uncertainty.type_b_nu/1.0.0/2026-09-16.o2-o3.083418691428.cvp.json"
  }
}