How can we get all external forces forces?

[victorkemp]

I'm looking for how to find all external forces, such as what you might use to do a force balance. We have various forces in the output:

/ANIM/VECT/FEXT - applied forces
/ANIM/VECT/FREAC - reactions at imposed displacements/etc.
/ANIM/VECT/FOPT - at rigid bodies/etc.
/ANIM/VECT/FINT - internal forces

The sum of FEXT and FREAC seems like it should be that, but I notice that at an interface on a VOID node, FREAC and FEXT are equal, so summing them might double-count those forces?

Or maybe it's negative FINT? That seems to end up including both applied and reaction forces.