訂正:
    (unless (and (boundp 'load-this-part-p) load-this-part-p) BODY )
                    →
   (if (and (boundp 'load-this-part-p) load-this-part-p) (progn BODY ))

_________________
If T is consistent then T !|- R_T
If T is consistent then T !|- ¬R_T. -- John B. Rosser