4.3 Car, Cdr

LVAL xcar()
{
    LVAL list;
    list = xlgalist();
    xllastarg();
    return (list ? car(list) : NIL);
}

LVAL xcdr()
{
    LVAL list;
    list = xlgalist();
    xllastarg();
    return (list ? cdr(list) : NIL);
}