anchor.diff:  	         extras_finish_step = keep_going
   	         call store_extra_info(s)
   
  -			 !evolve 100 steps then change to approx21_extras net
  +			 !set NET: evolve 100 steps then change to approx21_extras net
                if (s% model_number == 100) then
   				
   				write(*,*) '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  
positive.code: 			 real(dp), parameter :: huge_dt_limit = 3.15d16 ! ~1 Gyr
  	         extras_check_model = keep_going
  			 
  			 !increase varcontrol when the model hits the AGB phase
  			 if ((s% initial_mass < 10) .and. (s% center_h1 < 1d-4) .and. (s% center_he4 < 1d-4)) then
  				 s% varcontrol_target = 1d-3
  				 write(*,*) '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  	 			 write(*,*) 'increasing varcontrol to', s% varcontrol_target
  	 			 write(*,*) '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  			 end if
               
               !check for the first thermal pulse
              !if (s% center_he4 < 1d-4 .and. & 
              ! any(s% burn_he_conv_region(1:s% num_conv_boundaries)) & 
              ! .and. s% he_core_mass - s% c_core_mass <= &
              ! s% TP_he_shell_max) then
  			! 
  			! 	orig_eta = s% Blocker_wind_eta
   			! 	target_eta = 0.55
              ! 	s% varcontrol_target = 5d-3
  			! 
              ! 	if (orig_eta < s% Blocker_wind_eta) then !only print the first time
              ! 		write(*,*) '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
  			!		write(*,*) 'reducing varcontrol to', s% varcontrol_target, '  and increasing eta to a target value of ', target_eta
  			!	    write(*,*) '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++'
              !	end if
  			! 
  			!	if (s% Blocker_wind_eta < target_eta) then
  			!	  s% Blocker_wind_eta = s% Blocker_wind_eta + 0.05
  			!	  write(*,*) 'eta is at a value of ', s% Blocker_wind_eta
  			!	end if
  			! end if 
  			 
  			 !cap the mass loss at 1e-3 M/yr
  			 s% star_mdot = max(-1e-3, s% star_mdot)
  
               !turn off burning post-AGB
  			 envelope_mass_fraction = (s% star_mass - s% c_core_mass)/(s% star_mass)
  			 L_He = s% power_he_burn*Lsun
  			 L_tot = s% photosphere_L*Lsun
  
negative.code: 				 end if
  			 end if
  			 
  			 !define STOPPING CRITERION: stopping criterion for C burning, massive stars only.
  			 if ((s% center_h1 < 1d-4) .and. (s% center_he4 < 1d-4) .and. (s% center_c12 < 1d-4)) then
  			   	 termination_code_str(t_xtra1) = 'central C12 mass fraction below 1e-4'
                   s% termination_code = t_xtra1
  			   	 extras_check_model = terminate
  			 end if
  			 
  		     !check DIFFUSION: to determine whether or not diffusion should happen 
  	 	     if(s% do_element_diffusion) then !only check if diffusion is on
  	             if(abs(s% mass_conv_core - s% star_mass) < 1d-2) then ! => fully convective
  	 	            s% diffusion_dt_limit = huge_dt_limit
  