15. HexMatrix: dense matrices and arithmetic🔗

1. 15.1. Introduction
2. 15.2. The dense matrix type
3. 15.3. Arithmetic worked example
4. 15.4. Entry, row, and column lemmas
5. 15.5. Elementary operations
6. 15.6. Worked example
7. 15.7. The Mathlib correspondence
8. 15.8. Cross-references