anchor.diff:    use arguments, only: read_opt, read_opt_arg
     use parser, only: parser_nfields,remove_comments, parse_next_line
     implicit none
  -  
  +
     character(len=string_size) :: data_type
     integer                    :: nvars=0, nclasses=0
     integer,       allocatable :: seqs(:,:)
  
positive.code: ! Copyright (C) 2015-2017, Simone Marsili 
  ! All rights reserved.
  ! License: BSD 3 clause
  
  
negative.code:   character(len=long_string_size) :: frmt
    character(len=long_string_size) :: line, parsed_line
    integer :: flag=0 ! 1: u -> f; 2: f-> u
    integer :: nerrs=0
  
    call units_initialize()
  
    ! read arguments
    call get_command(cmd)
    nargs = command_argument_count()
  
    ! call with no args
    if (nargs == 0) then
       write(0,100)
       stop
    end if
  
  