Short answer - nowhere.
Rationale:
XLISP is a very simple Lisp. Many of the XLISP functions are just simple
wrappers around the underlying 
The main trick of Nyquist is to use XLISP only in the initial setup
phase, where the Lisp code is parsed, to 
Because the Nyquist 
I usually work with 
I first copy the 
When the 
I have tried to keep the functions as 
There are many XLISP functions that behave exactly like their
If you already know 
If you still don't know 
In either case you can use the Nyquist