Linear Algebra — Content Fill Progress

Status: ✅ Complete (2026-05-20)

Sections

• Linear systems of equations (23411) — 36 nodes filled
• Matrices (23447) — 147 nodes filled (incl. 17 Echelon children + 23 siblings)
• Linear systems and matrices (23751) — 25 nodes filled
• Vector spaces (23775) — 57 nodes filled
• Applications (24113) — 8 nodes filled (2 inaccessible: 403)

Summary

Total: ~273 nodes filled across 5 sections.

Empty nodes (not in scope)

• 24121, 24122 — 403 Forbidden (deleted/owned by another user)
• External nodes (116, 316, 424, etc.) — Parent/root nodes from other topics

Content Coverage

• Basic terminology — All foundational definitions
• Gaussian elimination — REF/RREF, Gauss-Jordan, extended RREF with four subspaces
• Matrix theory — Operations, types, decompositions (LU, QR, SVD), canonical forms
• Invertible Matrix Theorem — 30+ equivalent conditions
• Vector spaces — Coordinate and abstract, subspaces, bases, dimension, isomorphism
• Linear transformations — Kernel, range, isomorphisms, eigenvalues, Cayley-Hamilton
• Applications — Differential equations, Markov chains, coding theory, Leontief model