The *obarray* system variable contains the system symbol table. This symbol table is an XLISP array that is constructed out of lists.
(defun lookin (sym)                  ; create a function to
  (aref *obarray*                    ;   look inside *OBARRAY*
    (hash sym (length *obarray*))))  ;   and look for a specific
                                     ;   symbol - returns a list
(lookin "CAR")                       ; returns (TEST PEEK CAR)
(lookin "car")                       ; returns NIL
Note: When looking into *obarray* or interning symbols, remember that "car" and "CAR" written as strings [with quotation marks in front and behind] are two different symbols in *obarray*. Remember also that normal symbols created by XLISP are upper case names. So, if you type in 'car as a normal symbol [with a single quote in front of it], it will be the symbol CAR after this normal upper-casing operation.
See the
*obarray*
system variable in the