{"id":"euclids-elements","domain":"geometry","type":"Work","title":"Euclid's Elements","slug":"euclids-elements","url":"/mathematics/geometry/euclids-elements/","composed":"c. 300 BCE","author":"Euclid of Alexandria","books":13,"summary":"13-book axiomatic treatment of geometry and number theory, derived from 5 postulates. Most widely used mathematics textbook in history. Contains first proof of infinitely many primes, Euclidean algorithm, and proof of Pythagorean theorem.","added_to_codex":"2026-05-27","last_verified":"2026-05-27","sources":[{"tier":1,"citation":"Heath, T.L. (1956). Euclid: The Thirteen Books of the Elements. 3 vols. Dover."},{"tier":1,"citation":"Hilbert, D. (1902). The Foundations of Geometry. Open Court."},{"tier":2,"citation":"Artmann, B. (1999). Euclid: The Creation of Mathematics. Springer."}],"relationships":[{"type":"contains_proof","target":"prime-number","label":"Infinitely many primes (IX.20)"},{"type":"contains_proof","target":"pythagorean-theorem","label":"Pythagorean theorem (I.47)"},{"type":"superseded_by","target":"hilbert-foundations","label":"Hilbert's Grundlagen (1899)"}],"entry_status":"live","reading_levels_available":["curious","exploring","deep_dive"],"completeness":1.0,"codex_version":"1.2"}