Way to use unmatched brackets to mark ends of an interval?

What platform (Mac, PC, Posix) and executable (in-browser or app, and which) are you using: perhaps I've encountered a bug, because my UI--GeoGebra Classic, in Chrome, on a Mac--won't even let me enter in the text command you're displaying (it automatically balances the parentheses, and won't let me delete just the right-hand one)?

It will work in Classic 5, or you can use

UnicodeToLetter(40)

Again, the unbalanced brace problem.

I even tried cut-pasting precisely what you provide above and it automatically removes the "}." I'll try to make and post a "video screen shot" so you can see what I'm experiencing.

Environment details:

Geogebra Classic Version 6.0.581.0-w (07 May 2020)

Chrome Version 81.0.4044.129 (Official Build) (64-bit)

MacOS 10.15.4

Attached is a screen recording of me trying to enter in single (i.e., unbalanced) left and right brackets. First, I try to enter in just left brackets from my manual keyboard: the UI automatically closes them, which is fine, until I try to delete the right one, and it either doesn't delete just the right one, or it deletes both. Next, I try to enter in just right brackets from the manual keyboard: you can't see anything happening for a bit because I'm pressing the ")", "]", and "}" keys, but nothing is being put on the screen! Finally, I try the in-app virtual keyboard: this is the most revealing because it too exhibits this limitation, and you can see me clicking on the keys! It begs the Q, if one can't enter in just right brackets, why is the key for them even in the UI?

Perhaps I have the app configured wrong (?), but I can't for the life of me figure out where I'm supposed to be able to configure it right. Environment details are in the Comment above. Let me know if I should submit a bug report. Thanks!

Attached is a screen recording of me trying to enter in single (i.e., unbalanced) left and right brackets. First, I try to enter in just left brackets from my manual keyboard: the UI automatically closes them, which is fine, until I try to delete the right one, and it either doesn't delete just the right one, or it deletes both. Next, I try to enter in just right brackets from the manual keyboard: you can't see anything happening for a bit because I'm pressing the ")", "]", and "}" keys, but nothing is being put on the screen! Finally, I try the in-app virtual keyboard: this is the most revealing because it too exhibits this limitation, and you can see me clicking on the keys! It begs the Q, if one can't enter in just right brackets, why is the key for them even in the UI?

Perhaps I have the app configured wrong (?), but I can't for the life of me figure out where I'm supposed to be able to configure it right. Environment details are in the Comment above. Let me know if I should submit a bug report. Thanks!

Also, based on what I see when I enter in the TableText command without the closed bracket, I don't think you understand what it is I'm trying to do.

OK, my extensive comment to which I tried to attach my screen recording exhibiting the problem appears to have vanished into the ether. I'm going to submit a bug report, and if this turns out not to be a bug for some reason, they can tell me over there.

Maybe my browser is screwed up somehow, because this forum page UI is behaving badly: first it showed that my post to which I tried to attach my screen video vanished, now it's showing that it posted twice, but neither appears to have the attachment, and I can't seem to delete the above comment saying that that post vanished! What the heck is going on?

However, I'm not (yet) experiencing any problems on any other pages, plus it's Google Chrome, so I'm inclined to suspect the page code is at fault, not the browser.

It will work in Classic 5, or you can use

UnicodeToLetter(40)

You said that already; I'm using the unicode approach; very klugey.