anchor.diff:          stop
        end select
     end do args_loop
  +
  +  write(frmt,*) 
   
     call units_open_unf(rst_file,'old',unt,err)
     
  
positive.code:      end do
    end if
    k = 0
    do iv = 1,nvars
       do is = 1,nclasses
          k = k + 1
          write(*,'(i3,1x,i2,1x,f8.4)') iv,is,prm(k)
       end do
    end do
    do jv = 1,nvars-1
       do iv = jv+1,nvars
          do js = 1,nclasses
             do is = 1,nclasses
                k = k + 1
                ! order is inverted for printing 
                write(*,'(2(i3,1x),2(i2,1x),f8.4)') jv,iv,js,is,prm(k)
             end do
          end do
       end do
    end do
  
  
negative.code:         ! prm file
          iarg = iarg + 1
          call read_opt_arg(iarg,nargs,rst_file,err)
          if (err == 2) then
             write(0,*) 'ERROR ! missing argument: '//trim(arg)//' <filename>'
             stop
          end if
       case('-d', '--digits')
          ! the number of digits to the right of the decimal point
          ! default: print with full precision
          iarg = iarg + 1
          call read_opt_arg(iarg,nargs,n_digits,err)
          if (err == 2) then
             write(0,*) 'ERROR ! missing argument: '//trim(arg)//' <n>'
             stop
          end if
       case default
  