Start mathed, enter a short formula, put an overbrace over all of it, use ^ to
write "over" over the overbrace. So far so good.
Exit the math formula, then use left arrow to get into it again. Now you are in
a position after the overbrace, anything typed here will appear after the braced
formula.
If you move *two* steps to the left, you'll be inside the overbrace. Anything
typed in there will extend the overbrace.
But try moving only *one* step left! Then you get the cursor in a weird
position. Typing/inserting anything there will not extend the overbrace, but it
*will* steal the text over the overbrace and use it as an exponent. This must
be seen - it is strange. The effect is most dramatic if the overbrace is long
and the item inserted is something big, like a matrix. Or perhaps a long
formula from the paste buffer.
My guess is that this happens because overbrace with text is implemented as an
overbrace with an exponent? Coding it like that may be convenient, but this
came as a big surprise to me. At first, I could not understand why the "over"
text kept jumping around as I tried to put more formula under the brace.
I don't think the ability to shift the "over" text like that is useful, but it
sure is confusing. Try remembering to always use two leftarrows when going under
a brace with text over it, and try to apply that knowledge in a case where there
are two braces over each other ending at the same spot. Perhaps only one of
them have text over it too.
Suggested fix: skip over the useless cursor position.
Helge Hafting
