31.1. Introduction to Clifford Algebras31.2. Foundations31.2.1. Clifford Algebras and Rotations31.2.2. Higher-dimensional Clifford Algebra Rotations31.3. Examples of Clifford Algebras31.3.1. 1D Clifford Algebra31.3.2. 2D Clifford Algebra31.3.3. 2D Rotations Done Right31.3.4. 3D Clifford Algebra31.3.5. Clifford Implementation of 3D Rotations31.4. Higher Dimensions31.5. Pin(N), Spin(N), O(N), SO(N), and All That...