@christianp Another one missing from the list: open intervals.

I find (a, b) very confusing when I work with tuples in the same context.

On top of that, I find intervals with a single open end somewhat aesthetically unpleasing.

(a, b] seems to be the most prevalent notation. The bracket's "directions" match, though the bracket's types don't.

[a, b[ is a notation that seems to be popular in Germany, but which I haven't seen anywhere else much. (It's due to Bourbaki, I have been told)