anchor.diff:    (unless (get-buffer "*REPL*")
       (let ((*current-window* *current-window*))
         (inferior-lisp)))
  -  (let ((val))
  +  (let ((val)
  +        (error-p))
       (labels ((eval-thread-closure
                 ()
                 (let ((out
  
positive.code:         (push str *inferior-lisp-log*)
          (end-of-buffer)
          (insert-newline 1)
          (insert-string (write-to-string (safe-eval-from-string str)))
          (insert-newline 1)
          (insert-string "> ")
          (setq *inferior-lisp-last-point* (point))))))
  
  (define-key *inferior-lisp-mode-keymap* (kbd "M-p") 'inferior-lisp-prev)
  
negative.code:                                       (buffer-output-stream-linum out)
                                        (buffer-output-stream-column out)))))
                      (error (cdt)
                             (setq error-p t)
                             (setq val cdt))))))
               (mi-thread-closure
                ()
  