anchor.diff:      real(kind = x_precision),dimension(n_cell),intent(out) :: s              ! Surface density for the critical point
       !------------------------------------------------------------------------
       integer                                                :: i,j,k
  -    integer                                                :: file_length    ! Number of lines of the data saving file
   
       ! For the temperature and s
       real(kind = x_precision)                               :: temp
       real(kind = x_precision)                               :: Smin
       real(kind = x_precision)                               :: Smax
  -    real(kind = x_precision)                               :: Sigma          ! S
  +    real(kind = x_precision)                               :: Sigma          ! Sigma
   
       real(kind = x_precision)                               :: omega          ! Angular velocity
       real(kind = x_precision)                               :: r              ! Radius
  
positive.code: 
        enddo
  
        ! For the first critical point (the one one the right of the S shape)
        call first_critical_point(sigma_t_thick, temp_t_thick, index_fcp,sigma_c_thick, temp_c_thick, nb_it)
  
        ! For the second critical point (the one one the left of the S shape)
        call second_critical_point(sigma_t_thick, sigma_t_thin, temp_t_thick,&
         index_fcp, index_scp, sigma_c_thin, temp_c_thin, nb_it)
  
        ! Combining the two separate curves into one that forms the S shape
        call build_s_curve(sigma_t_thick, sigma_t_thin, temp_t_thick, nb_it, index_scp, sigma_real, temp_real)
  
        call display_critical_points(sigma_c_thin, temp_c_thin,sigma_c_thick, temp_c_thick, k)
  
  
        ! Saving the DIMENSIONED values of S and T for the S curve in a file
        write(number_of_cell,'(I5.5)') k
        fid_tot = 22 + k
        fname_tot = 's_curves/Temperature_Sigma_'//trim(number_of_cell)//'_tot.dat'
        
        open(fid_tot,file  = fname_tot, action='write',&
            status = 'replace', iostat = ios)
        if (ios /= 0) then
          write(*,*)"Error while opening the ", fname_tot," file."
          stop
  
negative.code: 
      implicit none
  
      integer                                  ,intent(in) :: n
      real(kind = x_precision),dimension(n)    ,intent(in) :: radius
      real(kind = x_precision),dimension(n)    ,intent(in) :: sigma_c_thin
      real(kind = x_precision),dimension(n)    ,intent(in) :: temp_c_thin
      real(kind = x_precision),dimension(n)    ,intent(in) :: sigma_c_thick
      real(kind = x_precision),dimension(n)    ,intent(in) :: temp_c_thick
      real(kind = x_precision),dimension(n)    ,intent(in) :: tau_thin
      real(kind = x_precision),dimension(n)    ,intent(in) :: tau_thick
      !-----------------------------------------------------------------------
      integer                                             :: i
      integer                                             :: fid_4 = 11
  