Initial 3-Track Book Codex & Exact Symbolic Engine (v0.1.0)¶
Established geometor/casey as the Digital Scriptorium edition and exact symbolic modeling library for John Casey’s A Sequel to the First Six Books of the Elements of Euclid (5th ed. 1888 / 6th ed. ed. P. A. E. Dowling 1892):
Multimodal Scan Inspection: Verified 38 archival folios at 300 DPI across Books I–IV, Book VI Sections I–VII, and the Supplementary Chapter on the Recent Elementary Geometry of the Triangle (PDF Folio = Printed Page + 26).
6-Unit 3-Track Book Codex: Published synchronized English, Summary, and Notes tracks across all six thematic units (unit-1 through unit-6) with 7 calibrated interactive
.euclid-graphicSVGs and full prosopographical (33 persons), bibliographic (22 works), glossary (30 terms), and cross-repository concordance apparatus.Exact Symbolic ``geometor.casey`` Package & 4 Runnable Demos: Proved Casey’s Generalized Ptolemy Theorem symbolically, constructed Feuerbach’s internal tangency at $F_e = X(11) = (6, 8)$ via Casey’s 1861 orthogonal inversion circle $(M_a, \frac{1}{2})$, verified coaxal pencils and Poncelet limiting points $L_1, L_2 = (\mp 8, 0)$, proved La Hire pole–polar reciprocity and harmonic secant ranges, and constructed Lemoine’s point $K = X(6)$, the First Lemoine & Cosine Circles, the 7-point Brocard Circle ($\Omega, \Omega', \triangle A_1 B_1 C_1$), Steiner’s point $X(99)$, Tarry’s point $X(98)$, and de Longchamps’ point $X(20)$ on the canonical $(15, 13, 14)$ Heronian triangle.