you don't need them in the language standard. Common Lisp is an extensible language and you would use one of the libraries available. > On the other hand, ther

you don't need them in the language standard. Common Lisp is an extensible language and you would use one of the libraries available. > On the other hand, there are many cases where relying just on cons, car, cdr, and related functions results in hard-to-read, hard-to-change code. That's why Common Lisp has structures and CLOS. One builds on top of those.