Hi, I recently released a book about mathematics and programming in github: https://github.com/liuxinyu95/unplugged I mainly provide examples, and code snippets in Haskell. The PDF can be downloaded under GNU FDL license. There are 7 chapters together with 108 problems as exercise. I also included all the answers in the appendix. Here are the table of content: Preface - A story about isomorphism. Chapter 1, Natural numbers. Peano Axiom, list and folding; Chapter 2, Recursion. Euclidean algorithm, Lambda calculus, and Y-combinator; Chapter 3, Symmetry. Group, Ring, and Field. Galois Theory; Chapter 4, Category theory and type system; Chapter 5, Deforest. Build-fold fusion law, optimization, and algorithm deduction; Chapter 6, Infinity. Set theory, Infinity and stream; Chapter 7, Logic paradox, Gödel's incompleteness theorems, and Turing halting problem. Answers to the exercise. Xinyu LIU https://github.com/liuxinyu95/unplugged *e*^(*π*i)+1 = 0