anchor.diff:      !------------------------------------------------------------------------
   
       do k = 1, n_cell
  -      file_length = 0
  -
         r     = r_state%r(k)
         omega = x_state%Omega(k)
   
  
positive.code:   ! Dichotomic function in order to determine the change of sign in a given
    ! interval [Smin,Smax] with an epsilon precision
    !-------------------------------------------------------------------------
    real(kind=x_precision) function dichotomy(S_min, S_max, max_it, eps, T, omega, optical_depth)
      implicit none
  
      real(kind=x_precision),intent(inout) :: S_min,S_max
      real(kind=x_precision),intent(in)    :: eps
      real(kind=x_precision),intent(in)    :: T
      real(kind=x_precision),intent(in)    :: omega
      integer,intent(in)                   :: max_it
      integer,intent(in)                   :: optical_depth
  
      integer                              :: j
      real(kind=x_precision)               :: tau_eff
      real(kind=x_precision)               :: Smin
      real(kind=x_precision)               :: Smax
      real(kind=x_precision)               :: f_min
      real(kind=x_precision)               :: f_max
      real(kind=x_precision)               :: f_center
      real(kind=x_precision)               :: S_center
  
  
      !-------------------------------------------------------------------------
      ! N-> Number of iterations for the dichotomy
  
negative.code:   use mod_read_parameters
    use mod_variables
    implicit none
  
  contains
    !-------------------------------------------------------------------------
  