Timo Heister

What is degree? Can you try 2d first if this is 3d?

No, the previous degree choice should be correct. It could be that the penalty term is too small for BDM. If we can not figure it out, we can leave...

How about we get this PR merged first without BDM (or just the lowest order pair)? Regarding the pressure solutions: these look like oscillating pressure due to a violation of...

Then it is unlikely to be inf-sup related.

> This might inherit from ReadWriteVector and LinearAlgebraVector and should conform to the new interface The whole point of the new system is that we need to import/export to/from a...

> We already ban using multiple threads with PETSc so this won't be an issue. Well, if we go forward with the plan, we no longer need to limit PETSc...

> I think that PETSc still keeps track of things at a global level, so one cannot create PETSc objects simultaneously across multiple threads without getting a race condition. I'll...

Many good ideas! I don't see a problem in general, but I can think of a couple of things to consider: - Functional style. It is worth considering a more...

> > Anisotropic refinement > > I personally never use it. Same here for similar reasons. I also don't believe in anisotropic refinement. ;-) The question is if you want...

@bangerth You are probably most familiar with ``compute_no_normal_flux_constraints``. Any suggestion on how to approach this?