anchor.diff:             prev_S = s%S
   
              ! Integrate S
  +           print *, 'S integration'
              call do_timestep_S(s, dt_V)
              ! Increment time
              t = t + dt_V
  
positive.code:   real(kind = x_precision)                    :: t_V, t_T  
    real(kind = x_precision)                    :: dt_V, dt_T
  
    t_V = params%t_nu / state_0%temps_0
    t_T = params%t_T / state_0%temps_0
    dt_V = t_V / 100._x_precision
    dt_T = t_T / 100._x_precision
  
    ! FIXME
    S_crit = 1.e99_x_precision
    ! FIXME
  
negative.code:   delta_T_max = 1e-2
  
    ! Initial time = 0
    t = 0._x_precision
  
    ! Read the parameters 
    call get_parameters()
  