npzd.h
#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
#if defined O_npzd_nitrogen_15
#endif
#if defined O_carbon_13
#endif
#if defined O_carbon_14
#endif
# if defined O_npzd
# if defined O_npzd_fe_limitation
# endif
# if defined O_save_npzd
#  if defined O_npzd_nitrogen
#   if defined O_npzd_extra_diagnostics
#   endif
#  endif
# endif
#endif