[ false swap
    dup size 1 > if
      [ [] temp put
        dup size factors
        -1 split drop
        witheach
          [ 2dup split drop
            dip [ over size swap / ]
            dup temp replace
            swap of over = if
              [ drop not
                temp share
                conclude ] ]
    temp release ] swap ]            is rep$ ( $ --> $ b )

  [ dup rep$ iff
      [ say 'The shortest rep-string in "'
        swap echo$
        say '" is "' echo$
        say '".' ]
    else
      [ say 'There is no rep-string for "'
        nip echo$ say '".' ]
    cr ]                             is task ( $ -->     )