Grown-up maths people who don't need to do exams any more: when's the last time you used interval notation?
I'm talking about things like (1,3] for "the interval between 1 and 3, including 3 but not 1".
@christianp occasionally, but it feels ambiguous enough in non-math papers to warrant a more explicit notation
@christianp I was explaining the group structure on elliptic curves, using rational points mod p. So I talked about the points being of the form (x,y) in [0,p)^2.
@christianp when I have to discuss intervals with other people I'm writing code with. Sometimes I still get thrown off by my French colleague using Bourbaki's \(]1,3]\).
@christianp Not lately, now that I think on it... But I don't regularly deal with continuous anything. And I'm not a topologist. There is very little cause for intervals in algebraic number theory.
@christianp Four days ago in a blog post https://11011110.github.io/blog/2021/09/24/which-integer-sequences.html
@christianp There isn't much call in what I've worked on for leaving off the endpoints of an interval. I looked up the instances I could remember offhand where we did have to do that (e.g., taking a parameter in the unit interval all the way to 0 or to 1 led to a degenerate case of some kind). We ended up not using the mixed-bracket notation in the final papers, though it's possible we used it on a whiteboard.
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!