anchor.diff:       (make-command-group
         :name ',name
         :supergroups ',supergroups
  -      :commands (list ,@commands))))
  +      :commands (let* ((commands (list ,@commands))
  +                       (dups (duplicates commands
  +                                         :test 'equalp
  +                                         :key (function command-initials))))
  +                  (when dups
  +                    (error "There are commands with duplicate initials: ~{~{~A~^, ~}~^; ~}."
  +                           (mapcar (lambda (dup)
  +                                     (mapcar (function command-name)
  +                                             (remove (command-initials dup) commands
  +                                                     :test-not (function string-equal)
  +                                                     :key (function command-initials))))
  +                                   dups)))
  +                  commands))))
   
   
   (defmethod find-command (command (group command-group))
  
positive.code: 
  
    #+developing
    (defcommand "DEASSEMBLER A PARTIR DE "     deux-numeros-optionels (from to)
      "Commande de deboguage: Désassemble les lignes de programme."
      (desassembler-a-partir-de from to))
  
    #+developing
    (defcommand "DP DEASSEMBLER/PERFORER A PARTIR DE "  deux-numeros-optionels (from to)
      "Commande de deboguage: Désassemble les lignes de programme."
      (io-start-tape-puncher *task*)
      (unwind-protect (desassembler-a-partir-de from to)
  
negative.code:                                                 :until (char= (aref chunk (1- (length chunk))) *nul*))
                                             (lse-data-file-close file))
                                           ""))))
              (io-format *task* "~2&~A~2&" source)
              (with-input-from-string (stream source)
                (dolist (line (compile-lse-stream stream))
                  ;; ENCODER merges the lines.
  