Hacker News with Generative AI: Algebra

Quaternions and spherical trigonometry (wordpress.com)
Hamilton’s quaternion number system is a non-commutative extension of the complex numbers, consisting of numbers of the form where are real numbers, and are anti-commuting square roots of with , , . While they are non-commutative, they do keep many other properties of the complex numbers:
Galois Theory (ph.utexas.edu)
The algebra and calculus of algebraic data types (2015) (recurse.com)
Grothendieck’s use of equality (arxiv.org)