eBook: [Chapter 2.2.3 Booleans](https://www.engineering.upenn.edu/~cis5000/current/sf-lean/lf/html/Basics/#Logical-Foundations--Basics___-Functional-Programming-in-Lean--Data-and-Functions--Booleans) ![[🧩 🧩 🧩 The nand' operation-1.png|648]] ## Important tactics used in this code snippet ![[match-tactic#match|match]] ![[infix-command#infix|infix]]