anchor.diff:      real(kind = x_precision),intent(in) :: sigma_c_thick
       real(kind = x_precision),intent(in) :: temp_c_thick
       integer                 ,intent(in) :: k
  +
       !------------------------------------------------------------------------
  +
       write(*,*)'**** Critical Point',k,'********'
       write(*,*)'****************************************'
       write(*,"(' Optically thin (T,sigma) :',1p,E12.4,4x,1p,E12.4)")temp_c_thin,sigma_c_thin
  
positive.code: 
        call display_critical_points(sigma_c_thin, temp_c_thin, sigma_c_thick, temp_c_thick, k)
  
  
        ! Saving the DIMENSIONED values of Sigma 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."
  
negative.code:     !-----------------------------------------------------------------------
  
      integer                                               :: i
  
      i = max(1, index_fcp)
  
  