Mathematics is a language that doesn't fit into ASCII and commonly uses one-character variable names. If you are implementing a documented mathematical algorithm (i.e. one with a description in a paper or book) then sticking to the notation of the paper (i.e. using one character variable names) makes sense to me.
Unfortunately, many of the things of this nature that you’ll want to implement use indices, which are inevitably going to start at 1. So you’ll still got plenty of hours of unpleasant debugging ahead of you, and a non-obvious correspondence to the original paper at the end of it.
I find math far easier to read when the authors use proper names for variables. But I understand that it isn't the idiomatic style and agree that it can be useful to match the paper when re-implementing an algorithm.