{ "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": "weighted-mean", "version": "1.0.1", "title": "Inverse-Variance Weighted Mean Calculator", "formula_family": "weighted-mean", "capability_id": "engineering.uncertainty.weighted_mean", "verification_revision": "2026-09-23.o2-o3" }, "profile": "engineering", "verified_scope": "JCGM 100 H.3 x_w = Σ(x_i/u_i²)/Σ(1/u_i²) and u_w = 1/√Σ(1/u_i²), plus χ² and Birge diagnostics, + O3 mpmath tabulated x_w.", "deferred_scope": "Not combined RSS, not Type A u_A = s/√n, and not expanded U = k·u_w.", "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": "weighted-mean", "version": "1.0.1", "uri": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/1.0.1.json", "verification_revision": "2026-09-23.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 — Guide to the expression of uncertainty in measurement (GUM)", "kind": "standard", "reference": "H.3 Measurements sampled from a distribution: weighted mean", "url": "https://www.bipm.org/en/publications/guides/gum.html" }, { "label": "JCGM 100:2008 — Combined standard uncertainty (RSS of a measurement model)", "kind": "standard", "reference": "5.1.2 uncorrelated input quantities" } ] }, "controls": { "CVP-PROV-01": { "result": "PASS", "applicability": "required", "notes": "Sources present on evidence" }, "CVP-MODEL-01": { "result": "PASS", "applicability": "required", "notes": "JCGM 100 H.3 x_w and u_w; O3 tabulated x_w" }, "CVP-SCOPE-01": { "result": "PASS", "applicability": "required", "notes": "Weighted mean of one measurand. Not RSS, not Type A, not U=k·u_w. O3 tabulated vectors only." }, "CVP-UNIT-01": { "result": "PASS", "applicability": "required", "notes": "x_i and u_i share an implied unit. χ² and Birge are dimensionless." }, "CVP-REF-01": { "result": "PASS", "applicability": "required", "notes": "O1 model + O2 expected_values + O2 numerical_behavior + O3 tabulated H.3" }, "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": "5/5 CVP boundary · 5/5 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=2; policy declared a priori" }, "CVP-COV-01": { "result": "PASS", "applicability": "required", "notes": "5/5 partitions (equal-weights, unequal-weights, single-result, alias, invalid-domain)" }, "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 weighted-mean; 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 @ 2026-09-24T03:01:27.868Z · live site-wide report stale @ 2026-09-24T03:01:44.278Z (104 other capabilities) · local checks pass · attestation_id=485d058427c8def04f9ec6c35dc0a2e115086cad7adaeb23f0886c27161d51fc · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-09-24T03:01:27.868Z · Live production status STALE (104 capabilities; 190 remain CURRENT) @ 2026-09-24T03:01:44.278Z · 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=e8d1161be1a15b9144a5af47ec3f09c44217605afff82cbb8d4b5d1ff406d635 · verified_at=2026-09-23T09:37:52.423Z · evidence_attested_at=2026-09-23T09:37:52.423Z · last_confirmed_current_at=2026-09-24T03:01:27.868Z · rendered_at=2026-09-24T03:01:44.337Z · binds=cvp_core_sha256", "check_result": "PASS", "production_state": "CURRENT", "binding_current": true }, "CVP-DIM-01": { "result": "PASS", "applicability": "applicable", "notes": "Inverse-variance weighted mean of one measurand" }, "CVP-PROP-01": { "result": "PASS", "applicability": "applicable", "notes": "2/2 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: JCGM 100 H.3 inverse-variance weighted mean vs separate-module identities (≤2 ULP). Not RSS, not Type A, and not U=k·u_w. ≤2 ULP vs O3 applies only to the published tabulated H.3 vectors (equal weights, unequal weights, a single result, aliases, a signed measurand, doubled uncertainties, and one awkward triple). It is not a whole-domain guarantee and does not cover RSS, Type A, or U=k·u_w." }, "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": "9dda804f701e9de80da80e44cac81652cc251dfb8e7df7fa1a0228b59de9cfd7", "evidence_digest": "77bc67046423c95952fddc7752e5738c69cb765898ccf68a044e22dd3ce8de02", "production_sha256": "e8d1161be1a15b9144a5af47ec3f09c44217605afff82cbb8d4b5d1ff406d635", "attested_catalog_sha256": "52419a75f87381c846435bf92ff0e55cf76f17e9ed5af27a656ef9c8dade1355", "production_checks": [ { "id": "engineering.uncertainty.weighted_mean: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": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:evidence-sha256", "status": "pass", "detail": "85d7e4e244cd", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:semantic-contract", "status": "pass", "detail": "9/9", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean: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": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:cvp-manifest-public-origin-agree", "status": "pass", "detail": "engineering.uncertainty.weighted_mean/1.0.1/2026-09-23.o2-o3/engineering/77bc67046423", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z", "projection_compared": false }, { "id": "engineering.uncertainty.weighted_mean:cvp-latest-alias-agrees", "status": "pass", "detail": "engineering.uncertainty.weighted_mean/1.0.1/2026-09-23.o2-o3/engineering/77bc67046423", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z", "projection_compared": false }, { "id": "engineering.uncertainty.weighted_mean:cvp-immutable-manifest-fetch", "status": "pass", "detail": "public=200 origin=200", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:cvp-immutable-manifest-sha256", "status": "pass", "detail": "77bc67046423", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:cvp-latest-alias-matches-immutable", "status": "pass", "detail": "engineering.uncertainty.weighted_mean/1.0.1/2026-09-23.o2-o3/engineering/77bc67046423", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z", "projection_compared": false }, { "id": "engineering.uncertainty.weighted_mean:cvp-reproduce-manifest-agree", "status": "pass", "detail": "2026-09-23.o2-o3 · 36fd74913f6b", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:calculator-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" }, { "id": "engineering.uncertainty.weighted_mean:evidence-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-23T09:37:52.423Z" } ], "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": "77bc67046423c95952fddc7752e5738c69cb765898ccf68a044e22dd3ce8de02", "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": "77bc67046423c95952fddc7752e5738c69cb765898ccf68a044e22dd3ce8de02", "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": "85d7e4e244cd9cd3c93134536011b449dbc8cc7c3d7e8b084cb4eca21e322477", "note": "Published Evidence JSON core — Trust freshness / production bind subject" }, { "name": "evidence_catalog_digest", "field": "artifacts.attested_catalog_sha256", "digest_scope": "capability_catalog", "value": "52419a75f87381c846435bf92ff0e55cf76f17e9ed5af27a656ef9c8dade1355", "note": "Capability catalog integrity; site-wide, not per-suite fingerprint" } ] }, "cvp_core_sha256": "77bc67046423c95952fddc7752e5738c69cb765898ccf68a044e22dd3ce8de02" }, "dependencies": [ { "name": "weighted-mean-engine", "version": "1.0.1" }, { "name": "weighted-mean-reference-oracle", "version": "1.0.0" }, { "name": "weighted-mean-mpmath-o3-table", "version": "weighted-mean-mpmath-o3" }, { "name": "node", "version": "20.19.2" } ], "attestation": { "status": "CURRENT", "href": "/.well-known/calculatorx-production-attestation.json", "id": "485d058427c8def04f9ec6c35dc0a2e115086cad7adaeb23f0886c27161d51fc", "attested_at": "2026-09-23T09:37:52.423Z", "last_confirmed_current_at": "2026-09-24T03:01:27.868Z", "site_attestation_current": false, "capability_attestation_current": true, "bound_snapshot_status": "pass", "live_report_status": "stale", "bound_attested_at": "2026-09-24T03:01:27.868Z", "live_updated_at": "2026-09-24T03:01:44.278Z", "bound_snapshot": { "status": "pass", "attested_at": "2026-09-24T03:01:27.868Z", "site_stale_count": 104 }, "live_site_status": { "href": "/.well-known/calculatorx-production-attestation.json" }, "bound_snapshot_site_stale_count": 104, "site_stale_capability_count": 104, "evidence_attested_at": "2026-09-23T09:37:52.423Z" }, "domain_review": { "status": "ABSENT", "spec_version": "1.0.1", "external_third_party": false, "note": "Named expert review not performed" }, "timestamps": { "verified_at": "2026-09-23T09:37:52.423Z", "generated_at": "2026-09-23T09:37:52.423Z", "rendered_at": "2026-09-24T03:01:44.337Z", "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": 5, "total": 5, "failed": 0 }, "boundary": { "passed": 5, "total": 5, "failed": 0 }, "invalid": { "passed": 7, "total": 7, "failed": 0, "comparison": "exact_error_match" }, "property": { "passed": 2, "total": 2, "failed": 0, "kind": "fixed", "claim_scope": "Enumerated identities: equal u_i → arithmetic mean and u_w = u/√n; a single result returns that result with Birge null. Not generated property tests." }, "round_trip": { "passed": 0, "total": 0, "failed": 0 }, "metamorphic": { "passed": 2, "total": 2, "failed": 0 }, "contract": { "passed": 6, "total": 6, "failed": 0 }, "cross_interface": { "passed": 4, "total": 4, "failed": 0 }, "o3": { "passed": 8, "total": 8, "failed": 0, "claim_scope": "O2: JCGM 100 H.3 inverse-variance weighted mean vs separate-module identities (≤2 ULP). Not RSS, not Type A, and not U=k·u_w. ≤2 ULP vs O3 applies only to the published tabulated H.3 vectors (equal weights, unequal weights, a single result, aliases, a signed measurand, doubled uncertainties, and one awkward triple). It is not a whole-domain guarantee and does not cover RSS, Type A, or U=k·u_w.", "max_error_ulp": 2, "table_sha256": "36fd74913f6b655063cf240a332366c7db4eb71231cc636c66af13fd0024aa27" } }, "numerical": { "representation": "IEEE-754 binary64", "tolerance": { "type": "ulp", "value": 2, "rationale": "Independent H.3 identities vs IUT on same V8 binary64. ≤2 ULP declared a priori.", "declared_before_evaluation": true }, "max_error_observed": 2, "claim_scope": "O2: JCGM 100 H.3 inverse-variance weighted mean vs separate-module identities (≤2 ULP). Not RSS, not Type A, and not U=k·u_w. ≤2 ULP vs O3 applies only to the published tabulated H.3 vectors (equal weights, unequal weights, a single result, aliases, a signed measurand, doubled uncertainties, and one awkward triple). It is not a whole-domain guarantee and does not cover RSS, Type A, or U=k·u_w." }, "coverage": { "partitions": [ { "id": "equal-weights", "description": "Two or more results with equal u_i, not an alias", "exercised": true, "case_count": 7 }, { "id": "unequal-weights", "description": "Two or more results whose u_i are not all equal", "exercised": true, "case_count": 6 }, { "id": "single-result", "description": "One result, so ν = 0 and Birge is undefined", "exercised": true, "case_count": 4 }, { "id": "alias", "description": "X / values / u_i / ux aliases", "exercised": true, "case_count": 3 }, { "id": "invalid-domain", "description": "Invalid inputs", "exercised": true, "case_count": 7 } ] }, "reference": { "items": [ { "class": "O1", "reference_scope": "model", "scope": "model", "label": "JCGM 100:2008 H.3 inverse-variance weighted mean" }, { "class": "O3", "reference_scope": "expected_values", "scope": "expected_values", "label": "Precomputed mpmath high-precision H.3 weighted mean (80 dps) rounded to nearest binary64 — not V8 Math", "engine": { "name": "weighted-mean-mpmath-o3", "library": "mpmath 1.4.1", "mpmath_dps": 80, "precision_bits": 265, "independent_of_iut": true, "same_runtime_as_iut": false, "generator_version": "1.0.0", "generator_sha256": "2baa044c7c7ee5d8ae102b3adae600083670248b894f331bd0106b1b24eee9b6", "table_sha256": "36fd74913f6b655063cf240a332366c7db4eb71231cc636c66af13fd0024aa27" } }, { "class": "O3", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O3 table vs IUT x_w, u_w, χ², and Birge; ≤2 ULP on tabulated vectors only", "engine": { "name": "weighted-mean-mpmath-o3", "library": "mpmath 1.4.1", "mpmath_dps": 80, "precision_bits": 265, "independent_of_iut": true, "same_runtime_as_iut": false, "generator_version": "1.0.0", "generator_sha256": "2baa044c7c7ee5d8ae102b3adae600083670248b894f331bd0106b1b24eee9b6", "table_sha256": "36fd74913f6b655063cf240a332366c7db4eb71231cc636c66af13fd0024aa27" } }, { "class": "O2", "reference_scope": "expected_values", "scope": "expected_values", "label": "Separate-module JCGM 100 H.3 weighted-mean oracle — same V8 binary64 as IUT", "engine": { "name": "weighted-mean-reference", "precision_bits": 53, "independent_of_iut": true } }, { "class": "O2", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O2 module backs ≤2 ULP x_w / u_w / χ² / Birge comparison vs IUT", "engine": { "name": "weighted-mean-reference", "precision_bits": 53, "independent_of_iut": true } } ] }, "links": { "legacy_evidence": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/1.0.1.json", "evidence_page": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/1.0.1", "calculator": "https://www.calculatorx.com/calc/engineering/weighted-mean", "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.weighted_mean/1.0.1.cvp.json", "manifest_immutable": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/1.0.1/2026-09-23.o2-o3.cvp.json", "reproduce": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/reproduce", "manifest_core": "https://www.calculatorx.com/evidence/engineering.uncertainty.weighted_mean/1.0.1/2026-09-23.o2-o3.77bc67046423.cvp.json" }, "disclosure": { "policy": "calculatorx-public-evidence-v1", "full_validation": "private", "representation": "summary" } }