(DEFINE LINEARIZE
,  (LAMBDA (SEXP)
,  ,  (COND
,  ,  ,  ((NULL SEXP) NIL)
,  ,  ,  ((ATOM SEXP) (LIST SEXP))
,  ,  ,  (T (APPEND (LINEARIZE (CAR SEXP)) (LINEARIZE (CDR SEXP))))
,  ,  ,,,)
,  ,,,)
,,,)