{ "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": "accuracy", "version": "1.0.1", "title": "Measurement bias", "formula_family": "measurement-accuracy", "capability_id": "engineering.measurement.accuracy", "verification_revision": "2026-09-25.o2-o3" }, "profile": "engineering", "verified_scope": "Signed bias x̄ − xm from repeats on a master, + O3 mpmath tabulated bias.", "deferred_scope": "Not Type A uncertainty and not a single-shot measurement error.", "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": "accuracy", "version": "1.0.1", "uri": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/1.0.1.json", "verification_revision": "2026-09-25.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 200:2012 — International vocabulary of metrology (VIM)", "kind": "standard", "reference": "2.13 measurement accuracy; 2.14 measurement trueness; 2.18 measurement bias", "url": "https://www.bipm.org/en/publications/guides/vim.html" }, { "label": "ISO 5725-1 — Accuracy (trueness and precision) of measurement methods and results", "kind": "standard", "reference": "Trueness as bias of the mean versus a reference" } ] }, "reference": { "items": [ { "class": "O1", "reference_scope": "model", "scope": "model", "label": "VIM trueness bias" }, { "class": "O3", "reference_scope": "expected_values", "scope": "expected_values", "label": "Precomputed mpmath bias (80 dps)", "engine": { "name": "measurement-accuracy-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": "84cb788992119c350dca0f7a7ad5f54cc2ab706527fde7fdc52672b12712c9c3", "table_sha256": "c1b8d10220e320e37a33829a7b05b2eff31935a0ef996f7a648bcdbc0e0353ee", "seed": "20260925.measurement-accuracy-o3", "source": "https://www.calculatorx.com/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "public_table": "/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "public_generator": "/developers/cvp/reproduce/generate-measurement-accuracy-o3.py" } }, { "class": "O3", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O3 table vs IUT bias; ≤2 ULP on tabulated vectors only", "engine": { "name": "measurement-accuracy-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": "84cb788992119c350dca0f7a7ad5f54cc2ab706527fde7fdc52672b12712c9c3", "table_sha256": "c1b8d10220e320e37a33829a7b05b2eff31935a0ef996f7a648bcdbc0e0353ee", "seed": "20260925.measurement-accuracy-o3", "source": "https://www.calculatorx.com/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "public_table": "/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "public_generator": "/developers/cvp/reproduce/generate-measurement-accuracy-o3.py" } }, { "class": "O2", "reference_scope": "expected_values", "scope": "expected_values", "label": "Separate-module bias oracle", "engine": { "name": "measurement-accuracy-reference", "precision_bits": 53, "independent_of_iut": true } }, { "class": "O2", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O2 module backs ≤2 ULP bias comparison", "engine": { "name": "measurement-accuracy-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": "Bias from a sample; O3 tabulated bias" }, "CVP-SCOPE-01": { "result": "PASS", "applicability": "required", "notes": "Not Type A. O3 tabulated vectors only." }, "CVP-UNIT-01": { "result": "PASS", "applicability": "required", "notes": "The sample and xm share one implied unit." }, "CVP-REF-01": { "result": "PASS", "applicability": "required", "notes": "O1 + O2 + O3" }, "CVP-GOLD-01": { "result": "PASS", "applicability": "required", "notes": "1/1 legacy golden; 4/4 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": "2 Evidence illegal-input + 2/2 oracle-backed error-code (exact_error_match, not ULP)" }, "CVP-NUM-01": { "result": "PASS", "applicability": "required", "notes": "max_error_observed_ulp=2; policy declared a priori" }, "CVP-COV-01": { "result": "PASS", "applicability": "required", "notes": "6/6 partitions" }, "CVP-CONTRACT-01": { "result": "PASS", "applicability": "required", "notes": "6/6 CVP contract · release-artifacts-aligned=PASS · schema-output-required-declared=PASS · schema-valid-input-executes=PASS · engine-success-output-validates-schema=PASS · schema-rejects-incomplete-input=PASS · rest-success-payload-validates-schema=PASS" }, "CVP-DEP-01": { "result": "PASS", "applicability": "required", "notes": "engine accuracy; 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 @ 2026-09-29T02:57:46.783Z · live site-wide report stale @ 2026-09-29T02:57:53.635Z (82 other capabilities) · local checks pass · attestation_id=32b8c8fc001c8156e721d1985f9285c24b4eb39419f1b706b7f4999d46ee806a · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-09-29T02:57:46.783Z · Live production status STALE (82 capabilities; 293 remain CURRENT) @ 2026-09-29T02:57:53.635Z · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.0.1 · 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 · cvp-reproduce-manifest-agree=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=1d85769a84c3c2dae1be22be2327b7597b376eab7bd4215d31b26b062abb3454 · verified_at=2026-09-24T22:06:19.759Z · evidence_attested_at=2026-09-24T22:06:19.759Z · last_confirmed_current_at=2026-09-29T02:57:46.783Z · rendered_at=2026-09-29T02:57:53.830Z · binds=cvp_core_sha256", "check_result": "PASS", "production_state": "CURRENT", "binding_current": true }, "CVP-DIM-01": { "result": "PASS", "applicability": "applicable", "notes": "Signed bias in the reading unit" }, "CVP-PROP-01": { "result": "PASS", "applicability": "applicable", "notes": "1/1 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": "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: signed bias vs a separate-module sample identity (≤2 ULP). Not Type A u_A and not a single-shot error. ≤2 ULP vs O3 applies only to the published tabulated bias vectors. Not Type A uncertainty." }, "CVP-EXP-01": { "result": "SKIP", "applicability": "optional", "notes": "named expert review not performed" } }, "tests": { "golden": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "g-low", "g-zero", "g-alias", "g-awkward" ] }, "boundary": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "boundary-acc-zero", "boundary-acc-flat", "boundary-acc-n1", "boundary-acc-missing" ] }, "invalid": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "boundary-acc-n1", "boundary-acc-missing", "inv-missing", "inv-short" ], "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-short", "comparison": "exact_error_match", "expected": { "code": "VALUE_OUT_OF_RANGE" }, "actual": { "code": "VALUE_OUT_OF_RANGE" }, "match": true } ] }, "property": { "passed": 1, "total": 1, "failed": 0, "case_ids": [ "prop-one" ], "kind": "fixed", "claim_scope": "Enumerated identity: values 6, 7, 8 and xm 8 give bias = −1 and s = 1.", "definition_ids": [ "six-seven-eight-against-eight-is-minus-one" ] }, "round_trip": { "passed": 0, "total": 0, "failed": 0, "case_ids": [] }, "metamorphic": { "passed": 1, "total": 1, "failed": 0, "case_ids": [ "meta-master" ], "definition_ids": [ "lowering-the-master-by-two-raises-bias-by-two" ] }, "contract": { "passed": 6, "total": 6, "failed": 0 }, "cross_interface": { "passed": 2, "total": 2, "failed": 0, "case_ids": [ "iface-low", "iface-missing" ] }, "o3": { "passed": 8, "total": 8, "failed": 0, "case_ids": [ "o3-low", "o3-zero", "o3-high", "o3-alias", "o3-flat", "o3-ddof0", "o3-awkward", "o3-wide" ], "generator_id": "measurement-accuracy-mpmath-o3", "seed": "20260925.measurement-accuracy-o3", "table_sha256": "c1b8d10220e320e37a33829a7b05b2eff31935a0ef996f7a648bcdbc0e0353ee", "max_error_ulp": 2, "reproduce": "python3 generate-measurement-accuracy-o3.py", "table_url": "/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "generator_url": "/developers/cvp/reproduce/generate-measurement-accuracy-o3.py", "claim_scope": "O2: signed bias vs a separate-module sample identity (≤2 ULP). Not Type A u_A and not a single-shot error. ≤2 ULP vs O3 applies only to the published tabulated bias vectors. Not Type A uncertainty.", "reproduce_url": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/reproduce" } }, "coverage": { "partitions": [ { "id": "alias", "description": "sample / X aliases", "exercised": true, "case_count": 2 }, { "id": "awkward", "description": "non-integer sample", "exercised": true, "case_count": 2 }, { "id": "ddof0", "description": "population standard deviation", "exercised": true, "case_count": 1 }, { "id": "low", "description": "mean below the master", "exercised": true, "case_count": 5 }, { "id": "zero", "description": "mean equal to the master", "exercised": true, "case_count": 5 }, { "id": "high", "description": "mean above the master", "exercised": true, "case_count": 2 }, { "id": "invalid-domain", "description": "missing master or a one-point sample", "exercised": true, "case_count": 4 } ] }, "numerical": { "representation": "IEEE-754 binary64", "claim_scope": "O2: signed bias vs a separate-module sample identity (≤2 ULP). Not Type A u_A and not a single-shot error. ≤2 ULP vs O3 applies only to the published tabulated bias vectors. Not Type A uncertainty.", "tolerance": { "type": "ulp", "value": 2, "rationale": "Independent sample identity vs IUT. ≤2 ULP declared a priori.", "declared_before_evaluation": true }, "max_error_observed": 2, "records": [ { "id": "g-low", "reference": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "golden" }, { "id": "g-zero", "reference": { "bias": 0, "abs_bias": 0, "xbar": 8, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": 0, "abs_bias": 0, "xbar": 8, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 7, 8, 9 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "golden" }, { "id": "g-alias", "reference": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "golden" }, { "id": "g-awkward", "reference": { "bias": -0.25, "abs_bias": 0.25, "xbar": 1.15, "s": 0.24999999999999994, "xm": 1.4, "n": 3, "ddof": 1 }, "actual": { "bias": -0.25, "abs_bias": 0.25, "xbar": 1.15, "s": 0.24999999999999994, "xm": 1.4, "n": 3, "ddof": 1, "values": [ 0.9, 1.15, 1.4 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "golden" }, { "id": "meta-master", "reference": 2, "actual": 2, "error_ulp": 0, "threshold_ulp": 2, "suite": "metamorphic", "hops": { "base": { "reference": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0 }, "follow": { "reference": { "bias": 1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 6, "n": 3, "ddof": 1 }, "actual": { "bias": 1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 6, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0 }, "relation": { "reference": 2, "actual": 2, "error_ulp": 0 } } }, { "id": "o3-low", "reference": { "oracle_layer": "analytic", "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-zero", "reference": { "oracle_layer": "analytic", "bias": 0, "abs_bias": 0, "xbar": 8, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": 0, "abs_bias": 0, "xbar": 8, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 7, 8, 9 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-high", "reference": { "oracle_layer": "analytic", "bias": 1, "abs_bias": 1, "xbar": 9, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": 1, "abs_bias": 1, "xbar": 9, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 8, 9, 10 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-alias", "reference": { "oracle_layer": "analytic", "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 1, "xm": 8, "n": 3, "ddof": 1, "values": [ 6, 7, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-flat", "reference": { "oracle_layer": "analytic", "bias": 0, "abs_bias": 0, "xbar": 8, "s": 0, "xm": 8, "n": 3, "ddof": 1 }, "actual": { "bias": 0, "abs_bias": 0, "xbar": 8, "s": 0, "xm": 8, "n": 3, "ddof": 1, "values": [ 8, 8, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-ddof0", "reference": { "oracle_layer": "analytic", "bias": -1, "abs_bias": 1, "xbar": 7, "s": 0.816496580927726, "xm": 8, "n": 3, "ddof": 0 }, "actual": { "bias": -1, "abs_bias": 1, "xbar": 7, "s": 0.816496580927726, "xm": 8, "n": 3, "ddof": 0, "values": [ 6, 7, 8 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-awkward", "reference": { "oracle_layer": "analytic", "bias": -0.25, "abs_bias": 0.25, "xbar": 1.15, "s": 0.25, "xm": 1.4, "n": 3, "ddof": 1 }, "actual": { "bias": -0.25, "abs_bias": 0.25, "xbar": 1.15, "s": 0.24999999999999994, "xm": 1.4, "n": 3, "ddof": 1, "values": [ 0.9, 1.15, 1.4 ] }, "error_ulp": 2, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 2 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "ok": true, "error_ulp": 0 } }, "suite": "o3" }, { "id": "o3-wide", "reference": { "oracle_layer": "analytic", "bias": 2, "abs_bias": 2, "xbar": 6, "s": 4, "xm": 4, "n": 3, "ddof": 1 }, "actual": { "bias": 2, "abs_bias": 2, "xbar": 6, "s": 4, "xm": 4, "n": 3, "ddof": 1, "values": [ 2, 6, 10 ] }, "error_ulp": 0, "threshold_ulp": 2, "fields": { "bias": { "ok": true, "error_ulp": 0 }, "abs_bias": { "ok": true, "error_ulp": 0 }, "xbar": { "ok": true, "error_ulp": 0 }, "s": { "ok": true, "error_ulp": 0 }, "xm": { "ok": true, "error_ulp": 0 }, "n": { "ok": true, "error_ulp": 0 }, "ddof": { "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": "aa37c72f6f6e4fffdffc247ccabb1cb9dbc8504343627d75dae4d9348e150daa", "evidence_digest": "cc85d911931167cfe7dbadaf6ea388cc423d132aa3b05b69cb7976c2fe4db9cf", "production_sha256": "1d85769a84c3c2dae1be22be2327b7597b376eab7bd4215d31b26b062abb3454", "attested_catalog_sha256": "9821b7afa172f562d1bf6535638d38ab8e6044ea84139444872d6c19047d1d21", "production_checks": [ { "id": "engineering.measurement.accuracy:output-const", "status": "pass", "detail": "output const 1.0.1 vs capability 1.0.1", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:evidence-sha256", "status": "pass", "detail": "960940774318", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:semantic-contract", "status": "pass", "detail": "9/9", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:capability-html-public-origin-agree", "status": "pass", "detail": "public 1.0.1 vs origin 1.0.1", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:cvp-manifest-public-origin-agree", "status": "pass", "detail": "engineering.measurement.accuracy/1.0.1/2026-09-25.o2-o3/engineering/cc85d9119311", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z", "projection_compared": false }, { "id": "engineering.measurement.accuracy:cvp-latest-alias-agrees", "status": "pass", "detail": "engineering.measurement.accuracy/1.0.1/2026-09-25.o2-o3/engineering/cc85d9119311", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z", "projection_compared": false }, { "id": "engineering.measurement.accuracy:cvp-immutable-manifest-fetch", "status": "pass", "detail": "public=200 origin=200", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:cvp-immutable-manifest-sha256", "status": "pass", "detail": "cc85d9119311", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:cvp-latest-alias-matches-immutable", "status": "pass", "detail": "engineering.measurement.accuracy/1.0.1/2026-09-25.o2-o3/engineering/cc85d9119311", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z", "projection_compared": false }, { "id": "engineering.measurement.accuracy:cvp-reproduce-manifest-agree", "status": "pass", "detail": "2026-09-25.o2-o3 · c1b8d10220e3", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:calculator-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" }, { "id": "engineering.measurement.accuracy:evidence-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-24T22:06:19.759Z" } ], "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": "cc85d911931167cfe7dbadaf6ea388cc423d132aa3b05b69cb7976c2fe4db9cf", "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": "cc85d911931167cfe7dbadaf6ea388cc423d132aa3b05b69cb7976c2fe4db9cf", "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": "960940774318cee4c3c2dfc8d95fcbc8650791edb25fb0fc500a613ba9a922b7", "note": "Published Evidence JSON core — Trust freshness / production bind subject" }, { "name": "evidence_catalog_digest", "field": "artifacts.attested_catalog_sha256", "digest_scope": "capability_catalog", "value": "9821b7afa172f562d1bf6535638d38ab8e6044ea84139444872d6c19047d1d21", "note": "Capability catalog integrity; site-wide, not per-suite fingerprint" } ] }, "cvp_core_sha256": "cc85d911931167cfe7dbadaf6ea388cc423d132aa3b05b69cb7976c2fe4db9cf" }, "dependencies": [ { "name": "accuracy-engine", "version": "1.0.1" }, { "name": "accuracy-reference-oracle", "version": "1.0.0" }, { "name": "measurement-accuracy-mpmath-o3-table", "version": "measurement-accuracy-mpmath-o3" }, { "name": "node", "version": "22.20.0" } ], "attestation": { "status": "CURRENT", "href": "/.well-known/calculatorx-production-attestation.json", "id": "32b8c8fc001c8156e721d1985f9285c24b4eb39419f1b706b7f4999d46ee806a", "attested_at": "2026-09-24T22:06:19.759Z", "last_confirmed_current_at": "2026-09-29T02:57:46.783Z", "site_attestation_current": false, "capability_attestation_current": true, "bound_snapshot_status": "pass", "live_report_status": "stale", "bound_attested_at": "2026-09-29T02:57:46.783Z", "live_updated_at": "2026-09-29T02:57:53.635Z", "bound_snapshot": { "status": "pass", "attested_at": "2026-09-29T02:57:46.783Z", "site_stale_count": 82 }, "live_site_status": { "href": "/.well-known/calculatorx-production-attestation.json" }, "bound_snapshot_site_stale_count": 82, "site_stale_capability_count": 82, "evidence_attested_at": "2026-09-24T22:06:19.759Z" }, "domain_review": { "status": "ABSENT", "spec_version": "1.0.1", "external_third_party": false, "note": "Named expert review not performed" }, "timestamps": { "verified_at": "2026-09-24T22:06:19.759Z", "generated_at": "2026-09-24T22:06:19.759Z", "rendered_at": "2026-09-29T02:57:53.830Z", "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.measurement.accuracy/1.0.1.json", "evidence_page": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/1.0.1", "calculator": "https://www.calculatorx.com/calc/engineering/measurement-bias", "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.measurement.accuracy/1.0.1.cvp.json", "manifest_immutable": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/1.0.1/2026-09-25.o2-o3.cvp.json", "reproduce": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/reproduce", "o3_table": "https://www.calculatorx.com/developers/cvp/reproduce/measurement-accuracy-o3-tables.json", "o3_generator": "https://www.calculatorx.com/developers/cvp/reproduce/generate-measurement-accuracy-o3.py", "manifest_core": "https://www.calculatorx.com/evidence/engineering.measurement.accuracy/1.0.1/2026-09-25.o2-o3.cc85d9119311.cvp.json" } }