fdifm.h
#if defined linearized_advection
#else
#endif
#if defined implicitvmix
#endif
#if defined consthmix && !defined biharmonic
# if defined neptune
# else
# endif
#else
#endif
#if defined consthmix
# if defined  biharmonic
# else
#  if defined neptune
#  else
#  endif
# endif
#endif
#if defined smagnlmix
#endif
#if defined stream_function
# if defined damp_inertial_oscillation
# else
# endif
#else
#endif