Unix only:
Using suffixed lyx, we install the lyx-desktop for different versions with
different file name, but with the same 'Name'-entry.
Selecting the desired version with the desktop menu is difficult if there
is more than one lyx version installed.
The current spelling is not strictly wrong, but flagged as unusual or
historical by some authorities. It is also found fault with many
spell checkers. Thus we decided to move to the more standard "-ible"
form once and for all.
See #10678 for discussion
This last part updates the layout format and changes collapsable color.
This will all also all be backported to 2.3.x, for the sake of backwards
compatibility (cherry-picking).
The current spelling is not strictly wrong, but flagged as unusual or
historical by some authorities. It is also found fault with many
spell checkers. Thus we decided to move to the more standard "-ible"
form once and for all.
See #10678 for discussion
This part covers the most tricky part: the internal naming.
Translations and layouts will follow.
This will all also all be backported to 2.3.x, for the sake of backwards
compatibility (cherry-picking).
The current spelling is not strictly wrong, but flagged as unusual or
historical by some authorities. It is also found fault with many
spell checkers. Thus we decided to move to the more standard "-ible"
form once and for all.
See #10678 for discussion
This part only covers the usage in comments and the like. More to follow.
This will all also all be backported to 2.3.x, for the sake of backwards
compatibility (cherry-picking).
In 1a26f9b26c, all strings in the context of regexes and
comparisons have been converted to byte-like objects for python2/3
compatibility reasons. This has not been considered in the later
commit 5c54557350, which makes layout2layout break with
TypeError: can't concat str to bytes.
The homepage does not exist anymore. Note that R installations now
come with Sweave already installed.
We now instead reference the user manual of Sweave.
Norman Ramsey is now at Tufts, and URLs to his websites at previous
institutions are broken. The new link gives the same information as
the old links did (verified with web.archive.org).
Dekel Tsur has a webpage with information on getting set up with
using Hebrew with LaTeX and LyX. We link to that webpage from our
Hebrew Tutorial. He appears to have changed universities, and the
new link gives the same information as the old link did (verified
with web.archive.org).
The wrapper script is placed in the binary directory of the LyX bundle.
It tries to find the real inkscape command line converter in the
Inkscape.app bundle and starts it or reports an error.
The configure.py is changed for Mac OS to check the presence of
the real inkscape binary in the Inkscape.app bundle.
Now painting the workarea is done at paint events as should be.
Explicit painting after updating metrics has been replaced by a much
lighter procedure (updatePosCache) to update the insets positions cache.
Expected benefits:
- better performance
- proper use of subpixel aliasing
The LyXRC variable use_qimage is not needed anymore and is therefore removed.
Remove the trimming operation on LabelString, LabelStringAppendix,
EndLabelString and LabelCounter. This trimming meant that quotes
strings were not preserved, which is wrong.
To preserve layouts, the Layout format has been updated to 64, so that
layout2layout can remove extra spaces on existing strings, which
ensures that behavior is unchanged for old layouts (courtesy of rgheck).
It is now possible to re-add spaces in label strings where it makes
sense.
Fixes bug #10723.
The inkscape command was hardcoded, but it seems that we need the full
patch on Windows. Therefore we check in configure.py if inkscape is
installed and pass the proper name (and possibly path) to the scripts.
Should address problems mentioned in #10679
The renaming happened in 2013. Contrary to what is stated in the
babel-vietnamese manual, option "vietnam" does not work anymore.
Also, the special care is note needed anymore, since language options
are not hardcoded anymore in babel.
Fixes: #10743
On TL17, the original default fonts used to work only with help of fix-cm package.
Only the Japanese bemer files are unchanged, because the output was only a mix
of Latin letters and thus not readable. Probably missing font on my side.
Evince is a special case, since it provides f/r search not via command
line switches and pref settings, but via DBUS. On Linux at least, this
can be used by LyX via some external scripts. The possibility is now
mentioned here, the details (and the scripts) are provided on the wiki.
- Move down the ERT icon
- Remove the transparent background from note icons as it turns out
not to be transparent on some combinations of platform/Qt version
This fixes an error in the preview generation with polyglossia
and bidi that prevents snippet generation (and consequently also
"math as image" xhtml output).
Fixes: #10716.
Due to the peculiarities of Windows, it may happen that
pdftocairo is built without png support when compiled on this
platform. Unless explicitly requested (maybe for some peculiar
application and certainly not for usual distros), this is
highly improbable to occur on other platforms.
1.) Handle also 'LatexCommand inputminted' in lyxStatus.pm
2.) Add '-shell-escape' to the appropriate converters.
This applies only to the ctest-environment iff calling
the script 'prefTest.pl' in the build directory.
Only the new field "List of Listings" with same translation as
for "Listings[[List of Listings]]" has been added. No other change
has been done, so layouttranslations might actually change again
when automatically updated.
This is for consistency with the newly introduced support in the
listings inset, where the option name is dictated by the listings
package and cannot be changed.
Update the listings inset to optionally use the minted package
(instead of the listings one) for typesetting code listings.
Only one of the two packages can be used in a document, but it
is possible to switch packages without issues if the used options
are the same. If a switch is made and the options differ, one needs
to manually adjust them if they were entered in the advanced options
tab, or apply again the gui settings.
Note that minted requires the -shell-escape option for the latex
backend and the installation of additional software (python pygments).
LyX correctly gave a warning about mixing InTitle layouts: There was
a LyX note in a Title environment, then there were standard
environments, and then a Title environment. This setup caused
several missing elements in the PDF.
Simply changing the Title environment of the Note to standard solved
the problems: The PDF output is now correct and LyX no longer gives
a warning.
The module allows to use the subequations environment.
There is still a pending request to implement this environment
natively in LyX's mathed.
Contributed by Joel Kulesza.
- add new vector images (the SVG files are only the sources and are therefore purposely not added to Makefile.am)
On the lyx-docs list it was reported that our current images look old and pixelated and I agree, so that I just draw new ones.
If we call parser.parse_args(), thus with no arguments, the parser uses
sys.argv (because that is the default). We should pass argv since that was
the purpose of handling argv in the main function.
We pass argv[1:] since when parsing the arguments we always ignore the name
of the program.
Use the full power of argparse to declare the default value of the end_format.
If we call parser.parse_args(), thus with no arguments, the parser uses
sys.argv (because that is the default). We should pass argv since that was
the purpose of handling argv in the main function.
With these changes, equation numbers are shown properly on screen.
When setting is default, we guess the side using these two rules
* ams(art|book) and siamltex classes are leqno by default. This is
signalled because the classes provide "leqno" (in amsdefs.inc). If
there are other classes that do this in output, the relevant classes
should be updated.
* the language arabic_arabi also sets leqno by default. This is
currently hardcoded for lack of a better idea.
Besides, a few bugs are fixed:
* use mathrm instead of mathbf for numbers metrics
* set spacing between maths and labels in inches
Remove support for python 1.x (really)
This code has not been used for a long time, probably never, since some code
above requires at least python 2.4 to work.
I got to this code by running futurize from python-future. There are no
significant warnings, mostly are related with the division but since
we are dividing floats there is no change between python 2 and 3.
python 2 does not allow to declare a string as raw byte so we double
the backslashes and remove the r preffix
python 3 accepts rb"..." meaning a byte string that is raw. In this context
raw means that the backslash does not has any special meaning and thus it
is not escaped. This is usefull together with regular expressions where the
backslashes are special.
In the worst possible case, like this one, we must use 4 backslashes to represent
one in the regular expression...
Setting the default working directory to '.' is an invasive change
on Mac and Windows, where the current working directory of LyX when
LyX is started from the GUI is not a reasonable choice for the
default directory in e.g. the "save as" file dialog or the "open"
dialog. A similar situation could happen on Linux distributions (I'm
not aware of any, e.g., POSIX standard that defines that the working
directory of a binary started from GUI should be the home
directory). Thus, it is not clear this default is good on any
platform.
If the user wishes to have the behavior of '.', the description in
the "paths" preferences pane provides the information for making the
change.
For more information, see the discussion at:
https://www.mail-archive.com/search?l=mid&q=635298DE-5028-4BB1-8D8F-A634BA68C420%40gmx.net
This reverts commit 892593fbdc.
- Adds a currentZoom variable which holds the current zoom level.
- The zoom stored in preferences is used as default zoom level (default binding:
M+0).
- The currentZoom is saved and restored via QSettings.
- Adds LFUN buffer-zoom for (re)setting zoom.
iconv fails, if a nomenclature inset contains an uncodable character
This led to failure of the indonesian UserGuide in the attic.
Fix it there and add a minimal, specific test sample instead.
Do not treat them as non-verbatim in conversion. This keeps math $...$
as math.
There will be problems with characters that are outside the given
encoding, but as long as there is no way to convert them to the
respective LaTeX macros from within lyx2lyx, I don't know how to solve
this.
as reported on the lyx-docs list this inset prevents the compilation of the file on Mac OS
It can be re-added when the bug is fixed (bug report follows soon by the original bug reporter)
New special character to mark an optional line break
without inserting a hyphen (ZWSP). See #10585.
Corresponds to the Unicode character U+200B ZERO WIDTH SPACE
This isn't a “space”. It is an invisible character that can be used
to provide line break opportunities.
http://unicode.org/notes/tn27/
While the literal Unicode character can be used in the LyX
file, it is invisible in the GUI.
For visible feedback, the patch adds a new special character "allowbreak".
The small mark is inspired by LibereOffice.
A tooltip is added.
The layout2layout.py script already reads and writes files in
binary format. However, all regexes and comparisons assume strings,
so that python3 chokes on them. This commit converts all involved
strings into bytes-like objects. In this way both python 2 and 3
behave the same.
Don't assume any encoding for the layout files and treat them in
the same way python 2 does. Thanks José for the idea.
This commit supersedes 50e21b71 and e19b2a71.
This patch fixes lyx2lyx running on python 3 for those systems
where the default encoding is not UTF-8, since open by default
uses the default system encoding.
Remove the duplicated \# -*- coding: utf-8 -*-
lines that show in the third line.
As far as I know they are not used, the first line though is used
by python and text editors (emacs, vi & co) to get the file encoding.
That will also work in the second lines (because of the shebang convention)
but not in other lines.
Remove trailing whitespaces.
Rephrase positively the check box for the output of en- and em-dashes
and disable it when using non-TeX fonts. The state of the check box
is remembered, so that toggling the non-TeX fonts check box does not
cause information loss.
- Mention the new buffer parameter in development/FORMAT
- Assure that lyx2lyx generates the same output obtained when saving
a converted document from within lyx
- Don't require any action when converting a document created with
lyx 2.2 in order to assure unchanged output (thanks José for the hint)
This commit fixes the regression introduced in 2.2 about the
output of en- and em-dashes. In 2.2 en- and em-dashes are output as
the \textendash and \textemdash macros when using TeX fonts, causing
changed output in old documents and also bugs (for example, #10490).
Now documents produced with older versions work again as intended,
while documents produced with 2.2 can be made to produce the exact
same output by simply checking "Don't use ligatures for en-and
em-dashes" in Document->Settings->Fonts.
When exporting documents using TeX fonts to earlier versions, in order
to avoid changed output, a zero-width space character is inserted after
each en/em-dash if dash ligatures are allowed. These characters are
removed when reloading documents with 2.3, so that they don't accumulate.
Handle name prefix (aka "von" part) as a separate entity, just like
BibTeX and Biblatex do. This allows to omit or reposition it in
accordance to the current style ("Goethe, Johann Wolfgang" or
"von Goethe, Johann Wolfgang" or "Goethe, Johann Wolfgang von" are all
valid and used).
LyX's name parser should now be on par with BibTeX's.
Yellow on blue causes display issues (some text elements that become black on
blue, math insets that are no longer readable). Switch to black on orange to
match the pdf output.
We don't invert unreliable tests for the same reason they are
inverted but, e.g., a nonstandard test that fails for some reason even with the
additional requirements installed or a test that shows wrong output
but also an error.
After a Theorem environment, LaTeX does by default indent the
following paragraph.
I checked various classes and no ModifyStyle was needed. The
hollywood and broadway classes are strange cases where there is an
indent after the Theorem environment, but it is much smaller than
the normal indent. The indent is the same as the opening indent of
normal text, which we currently ignore. Further, I don't expect it
is common to use theorems in these classes.
This empty inset caused problems with LuaTeX + system fonts (see
b863fb07). Although these problems seem to be resolved, this empty
inset is not supposed to be there.
This adds support for the chapterbib package, but also adds ways to
produce this sort of multibib with biblatex and bibtopic (which are
both incompatible with chapterbib).
File format change.
File format change.
This allows for the relevant InsetCommand-based dialogs (such as
citation text before/after, Bibitem label, hyperlink name etc.)
to provide both the input of verbatim code or text that is transformed
to proper LaTeX code.
Some dialogs (Nomencl, Href) already had some methods (although they
could not be toggled), which are now centralized and streamlined.
The initial work of this patch has been done by Georg Baum (see
http://www.lyx.org/trac/attachment/ticket/2751/x.diff)
Fixes: #2751, #8227.
These are biblatex-specific multicite commands that allow for multiple
pre- and postnotes, as in:
\cites(pre)(post)[pre1][post1]{key1}[pre2][post2]{key2}...
with an optional general pre- and postnote, which applies to the whole
list (like [][] in normal cite commands) and an optional pre- and
postnotes for each item, so that pagination can actually be specified in
multi-cite references, as in:
(cf. Miller 2015, 2; furthermore Smith 2013, 23-23; Jenkins 2012, 103,
also refer to chapter 6 in this book)
See the biblatex manual, sec. 3.8.3., for details.
File format change.
It seems that QTextLayout does not handle properly a single character
with 0 width. This breaks drawing of things like \not.
Actually the problem had been worked around already in lib/symbol. The
work around can therefore by removed now.
[additionally, remove extra spacing from \mapsto, \Mapsto]
Add FontEncoding tag for all languages with 8-bit hyphenation patterns
requiring a specific font encoding.
No FontEncoding tag means the language is either not supported with
Babel or accepts both, OT1 and standard text encodings.
Prerequisite for fontenc="auto" (ticket #9741)
Biblatex can be used with Japanese, but then, biber (not pbibtex) should
be used as processor.
I this context, bring the jbibtex UI in line with bibtex, allowing for
a selection of alternatives.
This is now set as default. It selects biber for Biblatex (with
fall-back to first bibtex8, then bibtex, if the former is not
installed), and bibtex for BibTeX-based engines.
With this, users do not normally need to care for the processor when
they switch cite engines.
Add common raster image viewing applications:
gwenview: KDE image viewer,
eog: Eye of Gnome, the Gnome default viewer,
xviewer: Eye of Gnome successor for MATE and Cinnamon,
ristretto: XFCE image viewer,
gpicview: LXDE image viewer,
lximage-qt: QXDE image viewer,
xdg-open: generic file handler
The problem with xdg-open is, that it calls the browser (firefox) as fallback. This is not good for DVI and PDF, but still better than an editor (Gimp) for raster images.
Kee Gimp as last option for viewing, and default choice for editing.
Place "notepad" at the end of the text editor selection list.
* Under Linux, notepad comes with the Windows emulator "wine"
but it is not a good choice for the default text editor.
* Most Windows users will not have the Linux programs
and not see any change.
* Windows users with the Windows version of "geany"
will see this (syntax highlighting) editor preferred over notepad by default.
'xed' is the 'gedit/plume' successor by Linux-Mint.
It inherits gedit's functionaly and adds a traditional UI matching the
XFCE, MATE and Cinnamon desktop environments.
See: https://de.wikipedia.org/wiki/X-Apps
'xreader' is the successor of 'evince' by Linux-Mint.
It inherits evince's functionaly and adds a traditional UI
matching the XFCE, MATE and Cinnamon desktop environments.
See: https://de.wikipedia.org/wiki/X-Apps
I don't know what happened with the version in master because it contained outdated sections I already removed months ago in branch. I can also not see new inf that is special in LyX 2.3dev.
Therefore I re-sync hereby with the version in branch.
As I often request: please change the doc files in branch, only new features of LyX 2.3 are master-only because there is no reason not to update and improve the docs for every LyX release.
Now only an adaptation of the Additional Features manual is needed,
but I leave this for now, since that manual apparently is undergoing
a major revision.
inset.
If the reference is "sec:mysec", then this will output just "mysec".
This is what is needed, e.g., to use refstyle's range commands, e.g.,
\secrangeref{mysec1}{mysec2}
You *cannot* use:
\secrangeref{sec:mysec1}{sec:mysec2}
even if those are the actual labels.
Eventually, I'd like to add native support for this, but I'm a bit
frightened of trying to make the reference dialog support multiple
selections.
This entails a change of getAbbrAuthor to getAuthorList (the default is
still abbreviated with respect to MaxCiteItems, but the list can be, at
explicit request, shortened or full notwithstanding MaxCiteItems.
We use the more comprehensive cochineal package if available and fall
back to the crimson package, if not.
Math support is provided by means of newtxmath
Fixes: #9974, #9976
* b `british' (``inner quotation'')
* w >>swedishg>> ('inner quotation') ["g" = Guillemets]
* f <<french>> (``inner quotation'')
* i <<frenchin>> (<<inner quotation>>) ["in" = Imprimerie Nationale]
* r <<russian>> (,,inner quotation``)
Rename "french" to "swiss"
Also rename "single/double" to "secondary/primary" ("inner/outer" in
the UI) and "left/right" to "opening/closing". Note that the inset
identifier string is left as is ("s/d" and "l/r")
The xfrac package is the "state of the art" for "split-level" (nice) fractions.
Character replacements look consistent, scale properly and fit in the line.
Fixes#5220.
This encoding (modified Mac Cyrillic for Asian languages) is rarely used and not supported by Gnu iconv.
Update comments in lib/encodings.
Update ctests: Gnu iconv only supports cp858, if configured with "--enable-extra-encodings".
The missing character problem is fixed upstream.
Also fix the scaling of the \sun-symbol-index by wrapping the symbol in \text.
(wasysym's \sun is valid in text and math mode. LyX currently adds a spurious \ensuremath.)
- Allow using logical values for icon sizes as the standard sizes may
differ among different icon sets
- Do not allow setting sizes smaller than smallIconSize
When the logical sizes differ and the icon set is changed, the correct
sizes are established only after a restart.
Addressing #10481.
This patch adds the new 'needauth' option for converters launching
external programs that are capable of running arbitrary code on behalf
of the user. These converters won't be run unless the user gives explicit
authorization, which is asked on-demand when the converter is about to
be run (question is not asked if the file is cached and calling the
converter is not needed).
The user prompt has a 3rd button so that he/she's not prompted again
for (any converter over) the same document (identified through
buffer->absFileName()).
Two preference options are added:
lyxrc.use_converter_needauth_forbidden disables any converter with
the 'needauth' option, which is meant to force user to an explicit
action via the preferences pane, before being able to use advanced
converters that can potentially bring security threats;
lyxrc.use_converter_needauth enables prompting the user for 'needauth'
converters, or bypasses the check if not enabled, falling back to the
previous behavior.
So, the first option is for maximum security, the second is for
maximum usability.
- Adds LFUNs for setting the icon size
- Adds icons sizes to the Toolbars menu
- Uses the Toolbars menu as application context menu
- The context menu can now be user defined in stdcontext.inc
Fixes ticket #10428.
Move math style to FontInfo and compute the font sizes for scriptstyle and
scriptscriptstyle according to standard proportions: 0.73 and 0.55.
This is simpler and more accurate. It also fixes the font size of
${\scriptscriptstyle {\textstyle A}}A$ which exposed the limitations of the
previous approach.
The purpose of this branch is to improve the spacing in math equations
* do not use hardcoded pixel values, but math units that depend on
zoom and dpi. This should be good for HiDPI systems.
* implement as much as possible the math typesetting algorithm
described in Appendix G of the TeXbook.
One typical example of the spacing algorithm is that ``-a'' has no
spacing, contrary to ``a + b''. This reflects the unitary/binary
minus that will indeed happen in typeset output.
Together with the better character substitution that has already been
implemented by Guillaume, we get a nice improvement of mathed looks.
What makes this code complicated is that it handles macros properly:
the spacing inside the macro will depend on the values of the
arguments and the elements that are before and after the macro.
As a result, many definitions in lib/symbols are now just copy/pasted
from the relevant sty file. In particular, it is now possible to make
use of \mathrel, \mathbin, etc. macros to specify spacing.
This merge is a starting point. Remaining work includes
* proper handling of sub/superscript nucleus and of font-changing
insets (as is done in the TeX algorithm).
* proper typesetting of fractions
Thanks to Guillaume for extensive testing.
Try as far as possible to use the same definitions as in the LaTeX files.
An example of that is the definition and subsequent use of \joinrel,
\relbar and \Relbar.
This is mostly Guillaume's work.
Test unicodesymbols for most supported input encodings with Kornel's addition to ctests.
Add required "forces" to unicodesymbols:
* utf8x does not support all characters supported by LyX
* several 8-bit encodings map characters to math-mode commands - force replacement in text-mode so that LyX can wrap them in \\ensuremath.
Fix a misalignment (wrong replacements) in the Cyrillic Unicode block.
Use \\mathscr for Mathematical Script characters in Mathematical Alphanumeric Characters (in line with the characters in other unicode blocks.
* set up a replacement of *, -, and : by the adequate symbols (#9893)
* fix the wrong character selection and operator spacing in \text mode
* hide some internal symbols from the auto-completion.
* Fix spacing in lib/symbols after recent commits about math spacing, as well as
older spacing issues (e.g. \Join).
* InsetMathKern now uses the same em value as other math length commands.
What is nice is that the kerning amount now matches the ones found in the
packages definition (modulo 10mu that lyx currently adds between relations).
Testcase: $\CheckedBox\LEFTcircle\RIGHTcircle\photon\gluon\vcentcolon\dblcolon\Coloneqq\eqcolon\models\hookrightarrow\bowtie\hookleftarrow\Join\APLinv\neq$
First run of Kornels patch for tests with all input encodings in lib/encodings.
Remove redundant sample files - keep only one sample and change the input encoding in the test script.
Put remaining failing test in "unreliableTests" for later sorting...
1. We must always output all (diverging) options, including
default options; if not, default options might get overwritten.
2. Do not output options in \setotherlanguage, since we might have
multiple "other languages" varieties from the same language (such
as naustrian, nswissgerman). And the options are output for the
language switches anyway.
Hence, LaTeXFeatures::getPolyglossiaLanguages() does not have to record
varieties. This was not done correctly anyway, since the map allowed
for one entry per language only.
- fileformat change
- I could not update the tex2lyx test files because of bug #10440
- maybe the lyx2lyx routine could be improved but since a document can also begin with another layout than "Standard" I could not use the lyx2lyx function put_cmd_in_ert
Do not use REVERSE SOLIDUS OPERATOR for backwards conversion of
\\\\textbackslash in LyX and tex2lyx.
Both, \\\\ (005C REVERSE SOLIDUS = backslash) and 0x29f5 map to
\\\\textbackslash but 005c is the preferred back-transformation.
Otherwise, using \\\\ in "mathematical text" leads to literal 0x29f5 in the LyX
source which leads to "missing character" errors with non-TeX fonts.
Ideally, we would use a proper counter here, but this seems to be
impossible with the current counter mechanism.
What we would need is a counter that is incremented when either of the
layouts is used. Currently, the counter seems to be stepped only inside
one layout.
The current fix is a candidate for stable.
Note that the lyxrc.document_path variable corresponds to what we
call the "Working directory" in the GUI preferences dialog.
Setting document_path to "." makes it so when LyX is started from a
directory, that directory is the default path for many of LyX's
operations, such as the following:
- new file, new from template
- adding a custom BibTeX file
- GUI compare dialog
- local layout button in document settings
- external material file browser
- graphics browser, include browser
The best guess for where the user wants to save or find files is the
directory the user started LyX from. Before, the default was always
the home directory. If desired, the old behavior can be restored by
changing the default path in Preferences > "Working directory".
This commit takes advantage of 9b64d7bd, which allows the use of a
relative path for path preferences.
* custom non-tex fonts with all required characters
* use 2.2 fileformat (easier backporting)
* test all export formats
Also, fix pattern for "mixing_inTitle_layouts" in unreliableTests.
force=utf8 is required for most characters provided by add-on packgages
and (almost) all mathematical characters, because these are not
set up for inputencs utf8
unicodesymbols.py failed here (python 2.7 under Linux) before the simple fix
included in this commit.
Based on Daniel Groger's work of five years ago, with minor changes
http://www.mail-archive.com/lyx-devel%40lists.lyx.org/msg169820.html
This extends the support for Xfig LaTeX + PDF to a more modern and
actively developed vector graphics editor. Embedded Objects manual
updated, also to include a workaround for an Inkscape 0.91 bug.
Specify non-TeX fonts that work in the source for documents that
fail with "missing characters" if compiling with "non-TeX fonts"=true.
(This does not interfere with the default output in any way.)
THe pdf output showed a very visible line overfull. I slightly changed the text to
avoid this without adding an hyphenation point, not appropriate in documents for beginners.
Use LyX note instead of comment. This is less invasive that
converting Beamer frames to fragile to accommodate the comment
environment.
(cherry picked from commit e81f6b04bc)
