I’m running into an annoying problem on my dissertation. Since it’s on tensors, I’m doing a lot of multidimensional indexing, and I find myself doing a lot of this:
Xi1,i2,…,in.
Now, Einstein notation lets me avoid writing sums (again, though, I’m not a fan of it, since there already exists a very nice Σ operator for sums), but it doesn’t do a thing for sequences like this one. In fact, I can’t find any operators that can represent this more concisely.
Now, I can probably treat i as a vector rather than a sequence of scalars, but that might confuse people.
If all else fails, I can probably define something like this:
X,j=1n
, with a big comma in that phrase similar to the huge sigma you use in a sum, but that’s difficult to represent, as the fact that I need to explain what I was writing demonstrates.
I’m leaning towards the vector solution, but if someone knows a good notation for this, please let me know.