Reply to msg by ALAN about PROG

[Guy.Steele at CMU-10A]

    Have you considered that instead of:
    
    (defmacro prog (vars &rest body)
      `(let ,vars (block nil (tagbody ,@body))))
    
    We might actually want:
    
    (defmacro prog (vars &rest body)
      `(block nil (let ,vars (tagbody ,@body))))
    
    The question being what does (prog ((a (return))) ...) mean?
    
That is a good question.  I did it the other way because I didn't
want (RESTART) to flush the variable bindings.  Obviously what
we do about RESTART will affect this.