. . . . "Drafted all Lean code and documentation; reconstructed and in places re-derived the proofs (see sub:faia). In a follow-up session, diagnosed and fixed the sole compile error and verified compilation under two toolchains (see sub:activity-verify). In a later session, generated the file's ISCC-CODE (see sub:activity-iscc). Not an author under prevailing scholarly norms; correctly credited by acknowledgment. All errors in the draft are attributable here, not to the mathematical tradition." . . . . . "Claude (Anthropic)" . "The axiomatic ideal the artifact rebuilds; the original tower (Elements, Book I), including target propositions I.47–I.48 (Pythagoras and converse) and Definition I.10, echoed in the planned `Per` (SST ch. 8)." . . "Intellectual ancestor" . "Euclid of Alexandria (fl. c. 300 BCE)" . "First machine-checked ascent of the SST development (Coq, from Narboux 2006 onward). The artifact reconstructs the GeoCoq architecture and navigated by its lemma map (l4_2 → inner_five_segment, l4_3 → cong_sub, l4_5 → cong3_construction, l4_6 → betw_transfer, l7_13 → reflect_cong, l7_15 → reflect_betw) but ports no GeoCoq code." . . "Formal ancestor" . "GeoCoq project (J. Narboux, M. Beeson, P. Boutry, G. Braun, C. Gries, P. Schreck, et al.)" . . "PhD dissertation, UC Berkeley 1965, under Tarski: axiom independence and simplification (several axioms are as lean as A1–A8 because of him), and the perpendicular and midpoint constructions without any continuity axiom — SST 8.18 and 8.22, the declared next stage of this artifact, not yet contained in it." . . "Axiom simplifier; author of the continuity-free constructions ahead" . "Haragauri Narayan Gupta (1925–2016)" . "Grundlagen der Geometrie (1899): the modern axiomatic program, and the segment arithmetic (Streckenrechnung, cf. SST ch. 14–15) that is the declared future route from this artifact to Pythagoras." . . "Program architect" . "David Hilbert (1862–1943)" . "Discovered that order is an assumption, not a triviality (Vorlesungen über neuere Geometrie, 1882). Namesake of axiom A7 (`inner_pasch`), on which the whole of Stage 2 rests: SST 3.1 (betw_trivial, indirectly), 3.2 (betw_symm), 3.5 (betw_inner_trans)." . . "Axiom source" . "Moritz Pasch (1843–1930)" . "Completed and published the treatise: Schwabhäuser, Szmielew, Tarski, 'Metamathematische Methoden in der Geometrie', Springer 1983. Every 'SST n.m' tag in the artifact cites all three authors through his numbering." . . "Systematizer and publisher" . "Wolfram Schwabhäuser (1931–1985)" . "Part I of SST grew from her lectures; the artifact follows her development lemma-for-lemma: SST 2.1–2.5, 2.8, 2.11, 2.12 (congruence calculus, segment addition, construction uniqueness); 3.1–3.3, 3.5, 3.6(1), 3.6(2), 3.7(1), 3.7(2) (betweenness calculus); 4.2, 4.3, 4.5, 4.6 (congruence–betweenness bridge); 7.4, 7.5, 7.13, 7.15 (point reflection and its isometry). She died before publication; her share of the credit is frequently understated." . . "Development author (followed lemma-for-lemma)" . "Wanda Szmielew (1918–1976)" . "The axiom system formalized as the `Tarski` typeclass, axioms A1–A8 (cong_pseudo_refl, cong_inner_trans, cong_identity, segment_construction, five_segment, betw_identity, inner_pasch, lower_dim), developed 1926–27; completeness and decidability of elementary geometry, guaranteeing the synthetic development agrees with EuclideanSpace ℝ (Fin n) on all first-order sentences. Survey citation: Tarski & Givant, 'Tarski's System of Geometry', Bulletin of Symbolic Logic 5(2), 1999." . . "Axiom-system author; metatheorist" . "Alfred Tarski (1901–1983)" . "Set the organizing question and metaphor (being 'trapped' in EuclideanSpace ℝ (Fin n) with only straightedge and compass), chose each descent (perpendiculars → compiling file → SST ch. 4 block → SST 7.13), and supplied the persistence that drove the artifact to zero `sorry`s. Directed the follow-up session that found a working Lean toolchain, compiled the artifact, and requested the fix for the sole compile error, and later directed the ISCC-CODE generation session. Holds the director's and verifier's credit." . . . . . . "Myles Axton" . . . . . . . . . . . . . . . "1e20eb61415a5383e8037259c33ad1bc4fe912516562a125c862e03648571b86d938" . "iscc-sdk - v0.9.4" . "ISCC:KAC67GWDV372567ANMUX3VYVTO7YIYHV2AILIDWJV3VWCQK2KOB6QAY" . "1e20bde6645eb61ec39e972274a1bd94924c754662a55ed8a84999eca3bd6eacdfc4" . . . . "28435 bytes (648 lines)" . "A synthetic development of Tarski's Euclidean geometry following Schwabhäuser–Szmielew–Tarski (SST) chapters 2–7: eleven axioms over two primitives (betweenness, segment congruence), developed through SST 7.13/7.15 (point reflection is an isometry). Zero `sorry`s. Compiles cleanly (`lean Tarski.lean` and `lake build`, exit 0) under both leanprover/lean4-nightly:nightly-2023-05-16 and leanprover/lean4:v4.32.0, confirming the dependency-free (core-Lean-4-only) claim across toolchain versions." . "text/plain" . "Tarski.lean" . "Lean 4 (core language only; no Mathlib dependency)" . "1372181e2284465648cf15fdd9b7a761ceef9288224feccfd71fb63a5417bfd1" . "Myles Axton thanks his father, Richard Axton (1941–2021), for his introduction to Euclidean geometry and the inspiration to do more with less (straight edge and compass only)." . . . "Dedication" . "Reconstruction of the SST/GeoCoq proof architecture from model memory; independent re-derivation where memory was insufficient (the SST 4.5 scaffold bookkeeping; SST 3.7(2) via mirror application of 3.7(1); the five-segment slot assignments in SST 7.13); translation into dependency-free core Lean 4; expository docstrings. In the follow-up session: diagnosed and fixed one compile error (the `example` at the end of Stage 5 used Mathlib's `∃!` unique-existence notation, unavailable in core Lean 4; rewritten as its explicit unfolding), then verified compilation. In a later session: generated the file's ISCC-CODE (see sub:isccNote, sub:activity-iscc)." . "Claude (Anthropic), Claude Fable 5, chat interface, sandboxed (no network, no Lean toolchain), for the original drafting session; Claude (Anthropic), Claude Sonnet 5, Claude Code CLI, with network and a working Lean 4 toolchain, for the subsequent compilation and fix session and for the ISCC-CODE generation session." . "Every construction and proof step was chosen or approved turn-by-turn in dialogue; the human set direction, scope, and the requirement of resolving all `sorry`s. The human also directed the follow-up build/fix/compile session and reviewed its result before this declaration was finalized, and directed the ISCC-CODE generation reported here." . "The artifact now compiles cleanly under two independent Lean 4 toolchains (see schema:description); this discharges the compilation-verification limitation noted in the original sandbox draft. An ISCC-CODE has now been minted (see sub:isccNote); remaining limitations: the mathematical content has not been cross-checked against an independent formalization (e.g. GeoCoq itself) beyond the lemma-map correspondence in sub:sst-map, and no trusted timestamp or ledger anchor has yet been obtained (see sub:timestampNote)." . "AI-drafted, human-directed" . "No new mathematics. Every theorem in the artifact is prior art carrying an SST number (see sub:sst-map). The creative contributions of the AI-human collaboration are formalization engineering and exposition only." . . . "ISO 24138 ISCC generation (Meta-, Content-, Data-, Instance-Code units) has now been completed using iscc-sdk v0.9.4, which wraps the iscc-core reference implementation (see sub:activity-iscc), superseding the earlier PENDING value. The .lean extension is not in iscc-sdk's recognized extension map, so content-based auto-detection (UTF-8 decodability, low control-character ratio) was used to process the file as text/plain, yielding a genuine text Content-Code rather than a raw-bytes-only fallback. The resulting ISCC-CODE, datahash, and metahash are recorded on sub:artifact. A trusted timestamp or ledger anchor for this document is still outstanding (see sub:timestampNote)." . . "ISCC binding status" . "Introduced Myles Axton to Euclidean geometry. The artifact's governing constraint — do more with less, straight edge and compass only — is his inspiration, and it is the same austerity that runs from Euclid's instruments through Tarski's two primitives to Gupta's removal of the continuity axiom." . . "Dedicatee; first teacher" . "Richard Axton (1941–2021)" . . "Lean name = SST number [= GeoCoq name where applicable]: cong_refl = 2.1; cong_symm = 2.2; cong_trans = 2.3; cong_left_comm = 2.4; cong_right_comm = 2.5; cong_trivial = 2.8; cong_add = 2.11 [l2_11]; construction_uniqueness = 2.12; betw_trivial = 3.1; betw_symm = 3.2; betw_left_trivial = 3.3; betw_inner_trans = 3.5; betw_exchange_left = 3.6(1); betw_exchange2 = 3.6(2) [between_exchange2]; betw_outer_trans = 3.7(1); betw_outer_trans' = 3.7(2); Cong3 = Def. 4.1 [Cong_3]; inner_five_segment = 4.2 [l4_2]; cong_sub = 4.3 [l4_3]; cong3_construction = 4.5 [l4_5]; betw_transfer = 4.6 [l4_6]; symmetric_point_exists = 7.4; symmetric_point_uniqueness = 7.5; reflect_cong = 7.13 [l7_13]; reflect_betw = 7.15 [l7_15]. Axioms A1–A8 = Tarski. Declared future work: Per = Euclid Def. I.10 / SST ch. 8; perpendiculars and midpoints = 8.18, 8.22 (Gupta); target theorem = Pythagoras, Euclid I.47–I.48, via segment arithmetic, SST ch. 14–15 (Hilbert)." . "Theorem-to-source concordance" . "All timestamps herein are the system clock of the drafting/verification/ISCC-generation sessions (self-asserted), not trusted timestamps. They are honest but not tamper-evident." . . "Timestamp status" . "A single sandboxed chat session beginning from the Pythagorean theorem in Mathlib's inner product spaces (norm_add_sq_eq_norm_sq_add_norm_sq_of_inner_eq_zero) and EuclideanSpace ℝ (Fin n), pivoting to the synthetic question, and building the Lean 4 artifact over successive turns. Sources were drawn from model memory of SST and GeoCoq; no network access and no Lean toolchain were available, so all proofs were verified by hand-tracing (and, for SST 7.13, by an additional coordinate check) rather than by compilation." . . "2026-07-19"^^ . "2026-07-18"^^ . . . . . . "Interactive formalization dialogue" . "Generated the ISCC-CODE (ISO 24138) for Tarski.lean using iscc-sdk v0.9.4 via a standalone content-identification workflow (iscc-workflow/generate_iscc.py). Fetched the commit-pinned GitHub blob (johnmaxton/lean4-starter @ 90018aec70b2bb8950c1045cac443731825d79ef) and confirmed it is byte-identical (same SHA-256) to the local working copy before generating the code. Because the .lean extension is unrecognized by iscc-sdk's mediatype map, content-based text auto-detection (added to the workflow for this case) was used to process the file as text/plain rather than a raw-bytes fallback." . . "2026-07-21"^^ . . . . "ISCC-CODE generation" . "A follow-up session with a working environment (network access, elan/Lean toolchains). Compiled `lean Tarski.lean` standalone and, separately, built it as a `lake` library target in two projects (pythagoras4, using leanprover/lean4-nightly:nightly-2023-05-16; and lean4-starter, using leanprover/lean4:v4.32.0). Found and fixed one error: the closing `example` used Mathlib's `∃!` notation, unavailable in core Lean 4, rewritten as its explicit unfolding. Both toolchains now build the file with zero errors and zero `sorry`s." . . "2026-07-18"^^ . . . . "Build, fix, and compilation verification" . . . . "Full transcript export (36 messages, participants 'Claude (Anthropic PBC)' and the human ORCID holder, per the export's own metadata) of the sandboxed formalization dialogue recorded as sub:activity; the source-of-record for this nanopublication's account of that session, ISCC-identified for tamper-evident reference." . "1e20ba75fff4f8f4c444367ab1a8b2a6dc174d8594a5e0a608629c783c3672ed9d13" . "iscc-sdk - v0.9.4" . "ISCC:KACVLHAC56XUUSQOQMH3UGAUADDVMRS5VJT3THHCNW5HL77U7D2MIRA" . "1e203058b6a3e88931d06f05aaf71f1baef07909f330d8d6fa48952fa3a8184e823f" . . . "2026-07-18T08:47:56Z"^^ . "2026-07-19T07:51:20Z"^^ . "application/json" . "Pythagorean theorem in Lean4 inner product spaces" . "Used from model memory as the formalization map; no code consulted or ported in-session." . . "GeoCoq repository and papers (Narboux et al., 2006–)" . "Used from model memory as the architectural source; not consulted directly in-session." . . "Schwabhäuser, Szmielew, Tarski — Metamathematische Methoden in der Geometrie (Springer, 1983)" . "2026-07-21T13:56:27Z"^^ . . . . "Provenance and credit declaration for Tarski.lean, a dependency-free Lean 4 formalization of Tarski's synthetic Euclidean geometry (SST chapters 2–7, Stages 0–4). Records intellectual lineage (Euclid through Gupta and GeoCoq), the AI-human authorship split, a dedication, and the file's ISCC-CODE (ISO 24138)." . . . "Tarski.lean provenance and credit declaration" . "2026-07-21T13:56:27Z"^^ . . . . . "RSA" . 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