{"id": "card_works_luhn", "kind": "verified", "title": "The check digit that catches a mistyped number", "body": "The Luhn and ISBN algorithms embed a check digit so a single wrong digit is caught before it becomes a wrong order or a wrong book. Two standards, both verified.  Worked & sealed by the engine — Luhn(4532 0151 1283 0366) is valid · ISBN-13 978-0-306-40615-7 is valid.  [HOLDS; open the seal to re-check.]", "source": {"label": "The Works — worked & sealed", "url": "https://narrowhighway.com/s/c7afd6622e881c44def4bb5327d8928d81bba9c5199dcfa0f2ee5b6f728b9992", "domain": "document_validation", "authority_tier": "verified"}, "shelf": "the-works", "box": "engineering", "bands": ["the-works", "engineering", "document_validation", "computation", "/", "validation"], "connections": [{"to_card_id": "card_spine_the-works", "relationship": "member_of", "evidence": "a member of the the-works shelf in the keeping"}, {"to_card_id": "card_k_floor_of_discovery", "relationship": "paves", "evidence": "A worked, engine-sealed demonstration — a paving-stone of the floor of reality."}, {"to_card_id": "card_v_50597b7a3831", "relationship": "demonstrates", "evidence": "A worked demonstration in the same field (document_validation)."}, {"to_card_id": "card_works_framing_square", "relationship": "adjacent", "evidence": "Neighbouring worked demonstrations in the same part of the volume."}, {"to_card_id": "card_works_exposure", "relationship": "adjacent", "evidence": "Neighbouring worked demonstrations in the same part of the volume."}, {"to_card_id": "card_works_ohms_law", "relationship": "adjacent", "evidence": "Neighbouring worked demonstrations in the same part of the volume."}], "author": "engine", "created_at": 0.0, "updated_at": 0.0, "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "generated": false, "subject": "Computation / validation", "extra": {"seal_hash": "c7afd6622e881c44def4bb5327d8928d81bba9c5199dcfa0f2ee5b6f728b9992", "cite_url": "https://narrowhighway.com/s/c7afd6622e881c44def4bb5327d8928d81bba9c5199dcfa0f2ee5b6f728b9992", "demonstration_id": "works_luhn", "verdict": "HOLDS"}, "presentation": {"glyph": "•", "kind_label": "engineering", "by": "The Works — worked & sealed", "authority": "verified", "posted": "", "standing": "", "link": {"url": "https://narrowhighway.com/s/c7afd6622e881c44def4bb5327d8928d81bba9c5199dcfa0f2ee5b6f728b9992", "host": "narrowhighway.com", "provider": "", "titled": "The check digit that catches a mistyped number", "waybill_line": "", "reach": "", "embed": ""}}, "neighbors": [{"id": "card_spine_the-works", "title": "The Works — sealed, worked demonstrations", "relationship": "on the shelf of", "why": "a member of the the-works shelf in the keeping", "href": "/card/card_spine_the-works", "resolved": true}, {"id": "card_k_floor_of_discovery", "title": "The Floor of Discovery — one floor, and by its design the fear of God", "relationship": "paves", "why": "A worked, engine-sealed demonstration — a paving-stone of the floor of reality.", "href": "/card/card_k_floor_of_discovery", "resolved": true}, {"id": "card_v_50597b7a3831", "title": "Luhn(4532 0151 1283 0366) is valid · ISBN-13 978-0-306-40615-7 is valid", "relationship": "demonstrates", "why": "A worked demonstration in the same field (document_validation).", "href": "/card/card_v_50597b7a3831", "resolved": true}, {"id": "card_works_framing_square", "title": "The 3-4-5 the builders use to square a corner", "relationship": "adjacent", "why": "Neighbouring worked demonstrations in the same part of the volume.", "href": "/card/card_works_framing_square", "resolved": true}, {"id": "card_works_exposure", "title": "The exposure value of a camera setting", "relationship": "adjacent", "why": "Neighbouring worked demonstrations in the same part of the volume.", "href": "/card/card_works_exposure", "resolved": true}, {"id": "card_works_ohms_law", "title": "A 12-volt circuit: the current it draws, the power it burns", "relationship": "adjacent", "why": "Neighbouring worked demonstrations in the same part of the volume.", "href": "/card/card_works_ohms_law", "resolved": true}]}