Bug 55086 - it is impossible to typeset an overlapping overbrace and underbrace pair
Summary: it is impossible to typeset an overlapping overbrace and underbrace pair
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Formula Editor (show other bugs)
Version:
(earliest affected)
unspecified
Hardware: Other All
: medium enhancement
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Formula-Editor
  Show dependency treegraph
 
Reported: 2012-09-19 09:35 UTC by Andras Timar
Modified: 2023-01-08 11:34 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
scanned image of the formula (9.93 KB, image/jpeg)
2012-09-19 09:35 UTC, Andras Timar
Details
Screenshot showing formula and rendering in v4.1.3.2. (15.74 KB, image/png)
2013-11-13 03:28 UTC, Owen Genat (retired)
Details

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Description Andras Timar 2012-09-19 09:35:51 UTC
Created attachment 67370 [details]
scanned image of the formula

It is impossible to typeset the attached formula in Math, while it is possible in LaTeX:

\documentclass[12pt]{article}
\usepackage{amsmath}
\begin{document}
\[
  \rlap{$\overbrace{\phantom{a+b}}^x$}a
     +\underbrace{b+c}_y
\]
\end{document}

The formatting command like \rlap is missing from Math.
Comment 1 Owen Genat (retired) 2013-11-13 03:28:28 UTC
Created attachment 89113 [details]
Screenshot showing formula and rendering in v4.1.3.2.

I am confirming this bug. Status set to NEW. There remains no elegant way to typeset the indicate formula in Math. Attached is a screenshot (taken under Crunchbang 11 linux running v4.1.3.2) showing an inelegant workaround, but the line spacing remains too great. Formula in the screenshot:

stack { 
alignl { { phantom { a "+" b } } overbrace x } #
a "+" b "+" c # 
alignr { { phantom { b "+" c } } underbrace y } 
}
Comment 2 Owen Genat (retired) 2014-03-15 23:03:14 UTC
Summary edited for clarity.
Comment 3 dante19031999 2020-06-28 12:04:54 UTC
You're right, but I'm not sure it can be implemented with the starmath actual system.
Comment 4 dante19031999 2020-07-04 04:44:17 UTC
I've been making further research on the matter.
The nodes system may support it, but not the parser.
Maybe it can be done. I'll try to do it, but gonna take at least one month.
Comment 5 Xisco Faulí 2021-02-09 13:18:06 UTC
Removing Assignee. No action done in a while
Comment 6 dante19031999 2021-02-09 15:56:45 UTC
(In reply to Xisco Faulí from comment #5)
> Removing Assignee. No action done in a while

This bug is impossible.
It is easy to introduce code for it in parser.
But I can't find any way to make it compatible with mathml.
Comment 7 Andras Timar 2023-01-08 11:34:23 UTC
<math display="block">
  <mrow>
    <mpadded width="0px">
      <mrow>
        <mover>
          <mover>
            <mphantom>
              <mi>a</mi>
              <mo>+</mo>
              <mi>b</mi>
            </mphantom>
            <mo stretchy="true" style="math-depth:0;">⏞</mo>
          </mover>
          <mi>x</mi>
        </mover>
      </mrow>
    </mpadded>
    <mi>a</mi>
    <mo>+</mo>
    <mrow>
      <munder>
        <munder>
          <mrow>
            <mi>b</mi>
            <mo>+</mo>
            <mi>c</mi>
          </mrow>
          <mo stretchy="true" style="math-depth:0;">⏟</mo>
        </munder>
        <mi>y</mi>
      </munder>
    </mrow>
  </mrow>
</math>