size.h
#if defined O_carbon
# if defined O_carbon_13
# endif
# if defined O_carbon_14
# endif
#endif
#if defined O_cfcs_data || defined O_cfcs_data_transient
#endif
#if defined O_npzd_alk
#endif
#if defined O_npzd_o2
#endif
#if defined O_npzd
# if defined O_npzd_nitrogen
#  if defined O_npzd_nitrogen_15
#  endif
# endif
# if defined O_carbon_13
#  if defined O_npzd_nitrogen
#  endif
# endif
#endif
#if defined O_carbon
# if defined O_carbon_13
# endif
# if defined O_carbon_14
# endif
#endif
#if defined O_npzd_alk
#endif
#if defined O_npzd_o2
#endif
#if defined O_npzd
# if defined O_npzd_nitrogen
#  if defined O_npzd_nitrogen_15
#  endif
# endif
# if defined O_carbon_13
#  if defined O_npzd_nitrogen
#  endif
# endif
#endif
#if defined O_carbon && defined O_carbon_co2_2d
#endif
#if !defined O_min_window
#else
# if defined O_fourth_order_tracer_advection || defined O_fct || defined O_quicker || defined O_pressure_gradient_average || defined O_biharmonic
#  if defined O_pressure_gradient_average
#   if defined O_biharmonic  || defined O_fourth_order_tracer_advection || defined O_fct || defined O_quicker
#   else
#   endif
#  else
#  endif
# else
# endif
#endif