Strong BASIC memories. On the Apple IIe, anything after the first two characters of variable names was ignored.

Do you always feel this is the case? To me the go to single letter variables are very readable. Used so widely my eyes parse them like other symbols: =, &, +, etc.

My rule of thumb: only using single letter variables in one-liners (and never if it spills to another line), or for something that is conventionally represented as such. So for example:

    ```python
    bar = [foo(e) for e in elements]
    ```

or, using `x`, `n`, `s` and similar when they represent just that, a generic variable with a number, string, etc. I think there is a Code Complete chapter about it.

Yeah, I'm not GP, but my exceptions to this rule are `i` for "iterator" in `for` loops and `e` for "event" in event listeners.

Don’t use ‘i’ (looks like 1), use ‘j1’, etc - helps set you up if you need a nested loop someday. Of course, at that point better naming would probably be best.

In real ok, but in this short example it‘s pretty obvious what t,b, r and c mean

It is also a math thing. most(if not all) constructions intended for mathematical consumption have some of the most miserable naming I have ever seen. I think it comes down to two things. when I am feeling less charitable it is that naming things is hard. so they don't bother. And when more charitable it is that they are optimizing for quick mental manipulation of a familiar machine. This tends toward the smallest variable names you can get away with, tons of implied context and compressed symbology. Of course this leaves the rest of us struggling, not with the concept but the way it is presented.

I like to joke, "you think programmers are bad at naming thing, you should see the mathematicians, programmers are infants before the infernal naming sense of the common mathematician".