firemath.info

I am trying to create notations for arcs of circles (with a curve over two to three capital letters) and I am unable to find that symbol in any of the notations.

Thanks for your time.

Within Firemath there is an 'OverParenthesis' button in the tabs panel at 'miscellaneous operators'. Enclose your capital letters by an <mrow> and add <munderover>-elements to that <mrow>. Place the OverParenthesis as the <mover>-element. Set the stretchy-attribute of the OverParenthesis to true.

Unfortunately, Firefox seems to have some bugs with respect to stretchy operators. See
https://bugzilla.mozilla.org/show_bug.cgi?id=416065
https://bugzilla.mozilla.org/show_bug.cgi?id=416140

If I misunderstood your question, it might help if you publish a LaTeX-expression here demonstrating what you intend to do.