@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)
A notation I invented and use myself in these cases are in fact square brackets with superimposed circles for open ends of intervals.
It is inspired by the way one may use to draw (half-)open line segments.
@esclear yes, good one! That reminds me to find the paper I started writing about parsing notation, where I collected a list of things like this
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