anchor.diff:    (initialize-environment)
     (xcvb-driver:debugging)
     #+clisp (setf *standard-input* *terminal-io*)
  -  (throw :repl nil))
  +  (invoke-restart 'rever-to-repl))
   
   (defun repl ()
     (let (/ // /// * ** *** + ++ +++ -)
  
positive.code: 
  (defun exit (&optional (code 0) &rest r)
    (declare (ignore r))
    (throw :exit code))
  
  (defun errformat (fmt &rest args)
    (apply #'format *error-output* fmt args))
  
negative.code: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Main ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  (defun main ()
    (with-coded-exit ()
      (restart-case
          ;; revert-to-repl is in a nested restart-case so that the other two
          ;; restarts are available from the repl.
          (restart-case
              (progn
                (interpret-command-line
                 (command-line-arguments:get-command-line-arguments))
                (quit 0))
            (revert-to-repl ()
              :report (lambda (stream)
                        (format stream "Abort current computation and bring up a toplevel REPL"))
              (repl)))
        (exit (&optional (exit-code 0))
          :report (lambda (stream)
                    ;; when invoked interactively exit-code is always 0
                    (format stream "Abort current computation and quit the process with process exit code 0"))
          (quit exit-code))
        (abort ()
          :report (lambda (stream)
                    (format stream "Abort current computation and quit the process with process exit code -1"))
          (quit 0)))))
  
  (defun initialize-environment ()
    #+sbcl (sb-posix:putenv (strcat "SBCL_HOME=" *lisp-implementation-directory*))
  