  Make sure all samples have an appropriate element factoring
  filter "factor-text-standard.gawk":
  
    # set trivialfilter = "/home/staff/stolfi/voynich/work/factor-text-trivial.gawk"
    # foreach sample ( ${samples} )
    #   set dir = "sample/${sample}"
    #   set filter = "${dir}/factor-text-standard.gawk"
    #   if ( ! ( -x ${filter} ) ) then
    #     ( cd ${dir} && ln -s ${trivialfilter} ${filter:t} )
    #   endif
    # end

