> When you look at Lisp function, it might do what you want, or it might not. There are no guarantees it does what it claims to do. Tests, contracts, type chec

> When you look at Lisp function, it might do what you want, or it might not. There are no guarantees it does what it claims to do. Tests, contracts, type checking - those are the guarantees. It's not unlike any other language.