For my thesis, I would like to use (light gray) underlines to indicate the rank of tensors. There are three modes: No underline, one underline and two underline. (For rank-0, rank-1 and rank-2 tensors.)
Currently, it looks like this:
Since the underlines are not essential, they should not disturb the reader. But I do not like, that the underlines are all at different heights.
Is there an easy way to have the underlines all the the same height?
I would not mind, if the underlines are in the background and the letters might overlap them a bit...
I know, underlines are an ugly idea, but in elasticity, there are many variables to keep in mind. Therefore, I would like to support the reader at least a little bit. But if I do not find a good notation, I will just drop the idea.
I don't want to use
\mathbb or other too fancy font modes. (These are sometimes used to denote rank-4 tensors already.)
I can not use lower or upper case to distinguish them, since this already indicates the domains and I want to stay close to my literature.