Re: [NTG-context] \overleftrightarrow
On Sat, 30 Jun 2007, Mojca Miklavec wrote:
On 6/29/07, Aditya Mahajan wrote:
Actually just adding overleftrightarrow is easy, but better will be an
interface to easily define such commands. So
If not, what can I do so that I can use it?
ConTeXt uses overleftarrow and overrightarrow as defined in plain
tex. This does not work in subscripts.
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
Here is a solution. First we patch math-ext so that arrowfills take a
style.
There are also underarrows, which will not be too hard to do. I will
patch math-ext with both overarrows and underarrows. I think that
there needs to be some italic correction for the arrow. It is
centered on the math box, but the math box is tilted to the right. Any
way to determine the correct horizontal skip that should be added.
I am attaching an updated math-ext.tex that defines over and under
arrows. To use it, copy it to your current directory and add \input
math-ext somewhere in your environment file.
Hans, this file also contains some minor typo corrections in the
earlier documentation. I have also changed the text width for comments
to 70, as 80 characters do not look nice on contextgarden.
Mojca, I remember that you had some trouble with overharpoons. Does
this take care of that?
\vec is not good for two reasons:
a) often stretchable arrows are needed (vectors both over single
letters and things like {AB} are mixed, and \vec looks really weird in
cases where letters are longer, or when we have combinations of them)
b) vectors should be harpoons (not arrows) according to our conventions.
My old \overrightharpoonup definitions had two other problems:
c) scalability/interfering with style change: you solved exactly that
one in a really nice way - thanks a lot (I did patch it, but it looked
like really ugly code)
d) glyphs themselves and their size (probably only the Polish guys can
help here) - and that's the real problem at the moment
Long ago, for some other problem, Taco had suggested that it will be
nice to have just the arrow heads. Then we could stack them the way we
want. IIRC, this is what the cow font does. If nothing else works, you
can try the cow font for writing math. I think that it matches nicely
with iwona-heavy :)
Consider
\def\myvec#1{\overrightharpoonup{#1}}
$(\myvec{\imath},\myvec{\jmath},\myvec{k})$ or $\myvec{\nabla}$,
$\myvec{\sigma}$, $\myvec{r}$, ...
The base size on top of i, j, k, ... is just too long and the harpoon
is also slightly too big.
A realy realy ugly solution (if you do not want extensible arrows).
\def\definemathshortarrow
{\dotripleargument\dodefinemathshortarrow}
\def\dodefinemathshortarrow[#1][#2][#3]%
{\ifthirdargument
\setvalue{#1}{\dohandlemathshortarrow[#2][#3]}%
\else
\setvalue{#1}{\dohandlemathshortarrow[\zeropoint][#2]}%
\fi}
\def\dohandlemathshortarrow[#1][#2]%
{\mathpalette{\dodohandlemathshortarrow{#1}{#2}}}
\def\dodohandlemathshortarrow#1#2#3#4%
[EMAIL PROTECTED]
\vbox{\ialign{##\crcr
[EMAIL PROTECTED]
\noalign{\kern#1\nointerlineskip}%
[EMAIL PROTECTED]
\definemathshortarrow [shortoverrightharpoonup]
[\rightharpoonup]
\let\myvec\shortoverrightharpoonup
I do not like mirror-clip-mirror but I could not find how to clip
from the left rather than the right.
I guess now is the time to update the myway on math arrows :)
Aditya
math-ext.tex
Description: Binary data
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Re: [NTG-context] overleftrightarrow
Quoting Aditya Mahajan [EMAIL PROTECTED]:
On Sat, 30 Jun 2007, Mojca Miklavec wrote:
Consider
\def\myvec#1{\overrightharpoonup{#1}}
$(\myvec{\imath},\myvec{\jmath},\myvec{k})$ or $\myvec{\nabla}$,
$\myvec{\sigma}$, $\myvec{r}$, ...
The base size on top of i, j, k, ... is just too long and the harpoon
is also slightly too big.
A realy realy ugly solution (if you do not want extensible arrows).
Here is a slightly better solution; I have tested it only for harpoons,
and there are no configuration options for other accents. But it
works for both short and long objects.
\def\definemathfancyarrow
{\dotripleargument\dodefinemathfancyarrow}
\def\dodefinemathfancyarrow[#1][#2][#3]% arrow short long
{\setvalue{#1}{\dohandlemathfancyarrow[#2][#3]}}
\def\dohandlemathfancyarrow[#1][#2]%
{\mathpalette{\dodohandlemathfancyarrow{#1}{#2}}}
%TODO: The clip operation should be configurable, whether you want to clip
%right or clip left.
\unexpanded\def\dodohandlemathfancyarrow#1#2#3#4% short long style text
[EMAIL PROTECTED]
[EMAIL PROTECTED]
\vbox{\ialign{##\crcr
\ifdim\wd0\wd2
[EMAIL PROTECTED]
\else
#2#3%
\fi\crcr
\noalign{\kern-\onepoint\nointerlineskip}%
[EMAIL PROTECTED]
\definemathfancyarrow [fancyoverrightharpoonup]
[\rightharpoonup]
[\rightharpoonupfill]
\let\myvec\fancyoverrightharpoonup
\starttext
$\myvec{\imath} \myvec{\jmath} \myvec{ABCD}$
\stoptext
Aditya
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Re: [NTG-context] \overleftrightarrow
Hi Aditya,
Aditya Mahajan [EMAIL PROTECTED] writes:
On Thu, 28 Jun 2007, Jesse Alama wrote:
I'm preparing a geometry course using ConTeXt and am impressed with the
system so far. One thing I need is to do is typeset various geometrical
symbols. It looks like ConTeXt already has the \overleftarrow and
\overrightarrow commands, but one thing I'd like to have is
\overleftrightarrow, for typesetting the symbol customarily used to
denote the line determined by two points. It seems, though, that this
isn't available in ConTeXt, or, at least, it is not available by
default. I tried looking on the contextgarden and google, but didn't
come across anything. Is the \overleftrightarrow command already
available?
Actually just adding overleftrightarrow is easy, but better will be an
interface to easily define such commands. So
If not, what can I do so that I can use it?
ConTeXt uses overleftarrow and overrightarrow as defined in plain
tex. This does not work in subscripts.
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
Here is a solution. First we patch math-ext so that arrowfills take a
style.
\unprotect
\def\mtharrowfill#1#2#3#4#5#6#7#8% AM: Added #8 (for displaystyle)
{$\mathsurround 0pt
\thickmuskip0mu\medmuskip\thickmuskip\thinmuskip\thickmuskip
\relax#8#5%
\mkern-#1mu
\cleaders\hbox{$#8\mkern -#2mu#6\mkern -#3mu$}\hfill
\mkern-#4mu#7$}
%D Now we need to make sure that the extensible arrows do not get
%D affected. So...
\def\domthxarr#1#2#3#4#5% hm, looks like we do a double mathrel
{\begingroup
\def\mtharrfactor{1}%
\def\mtharrextra {0}%
\processaction[#1] % will be sped up
[ \v!none=\def\mtharrfactor{0},
\v!small=\def\mtharrextra{10},
\v!medium=\def\mtharrextra{15},
\v!big=\def\mtharrextra{20},
\v!normal=,
\v!default=,
\v!unknown=\doifnumberelse{#1}{\def\mtharrextra{#1}}\donothing]%
\mathsurround\zeropoint
\muskip0=\thirdoffourarguments #2mu
\muskip2=\fourthoffourarguments #2mu
\muskip4=\firstoffourarguments #2mu
\muskip6=\secondoffourarguments #2mu
\muskip0=\mtharrfactor\muskip0 \advance\muskip0 \mtharrextra mu
\muskip2=\mtharrfactor\muskip2 \advance\muskip2 \mtharrextra mu
\setbox0\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#5\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\setbox4\hbox{#3\displaystyle}% AM: Added displaystyle
\dimen0\wd0
\ifdim\wd4\dimen0 \dimen0\wd4 \fi
\setbox2\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#4\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\ifdim\wd2\dimen0 \dimen0\wd2 \fi
\setbox4\hbox to \dimen0{#3\displaystyle}% AM: added dislaystyle
\mathrel{\mathop{\hbox to
\dimen0{\hss\copy4\hss}}\limits^{\box0}_{\box2}}
\endgroup}
\let\domthxarrsingle\domthxarr
%D Now, for defining overarrows.
\def\definemathoverarrow
{\dotripleargument\dodefinemathoverarrow}
\def\dodefinemathoverarrow[#1][#2][#3]%
{\ifthirdargument
\setvalue{#1}{\dohandlemathoverarrow[#2][#3]}%
\else
\setvalue{#1}{\dohandlemathoverarrow[\zeropoint][#2]}%
\fi}
\def\dohandlemathoverarrow[#1][#2]%
{\mathpalette{\dodohanglemathoverarrow{#1}{#2}}}
% Note: math-pln has \kern-\onepoint, amsmath does not. I keep the
% kern amount as an option. This is useful with overharpoons.
\def\dodohanglemathoverarrow#1#2#3#4%
{\vbox{\ialign{##\crcr
#2#3\crcr
\noalign{\kern#1\nointerlineskip}
[EMAIL PROTECTED]
\protect
\definemathoverarrow [overleftarrow] [\leftarrowfill]
\definemathoverarrow [overrightarrow] [\rightarrowfill]
\definemathoverarrow [overleftrightarrow] [\leftrightarrowfill]
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
$\overleftrightarrow{A}$ $\overleftrightarrow{ABC}$
$a_{\overleftrightarrow{A}}$ $b_{\overleftrightarrow{ABC}}$
As an added bonus:
\definemathoverarrow [overtwoheadrightarrow] [\twoheadrightarrowfill]
\definemathoverarrow [overtwoheadleftarrow] [\twoheadleftarrowfill]
\definemathoverarrow [overrightharpoondown] [1pt] [\rightharpoondownfill]
\definemathoverarrow [overrightharpoonup] [\rightharpoonupfill]
\definemathoverarrow [overleftharpoondown] [1pt] [\leftharpoondownfill]
\definemathoverarrow [overleftharpoonup] [\leftharpoonupfill]
$\overtwoheadrightarrow {XYZ}$
$\overtwoheadleftarrow {XYZ}$
$\overrightharpoondown {XYZ}$
$\overrightharpoonup {XYZ}$
$\overleftharpoondown{XYZ}$
$\overleftharpoonup {XYZ}$
There are also underarrows, which will not be too hard to do. I will
patch math-ext with
Re: [NTG-context] \overleftrightarrow
On Wed, 11 Jul 2007, Jesse Alama wrote:
Hi Aditya,
Aditya Mahajan [EMAIL PROTECTED] writes:
On Thu, 28 Jun 2007, Jesse Alama wrote:
I'm preparing a geometry course using ConTeXt and am impressed with the
system so far. One thing I need is to do is typeset various geometrical
symbols. It looks like ConTeXt already has the \overleftarrow and
\overrightarrow commands, but one thing I'd like to have is
\overleftrightarrow, for typesetting the symbol customarily used to
denote the line determined by two points. It seems, though, that this
isn't available in ConTeXt, or, at least, it is not available by
default. I tried looking on the contextgarden and google, but didn't
come across anything. Is the \overleftrightarrow command already
available?
Actually just adding overleftrightarrow is easy, but better will be an
interface to easily define such commands. So
If not, what can I do so that I can use it?
ConTeXt uses overleftarrow and overrightarrow as defined in plain
tex. This does not work in subscripts.
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
Here is a solution. First we patch math-ext so that arrowfills take a
style.
Cut Here
--%
\unprotect
\def\mtharrowfill#1#2#3#4#5#6#7#8% AM: Added #8 (for displaystyle)
{$\mathsurround 0pt
\thickmuskip0mu\medmuskip\thickmuskip\thinmuskip\thickmuskip
\relax#8#5%
\mkern-#1mu
\cleaders\hbox{$#8\mkern -#2mu#6\mkern -#3mu$}\hfill
\mkern-#4mu#7$}
%D Now we need to make sure that the extensible arrows do not get
%D affected. So...
\def\domthxarr#1#2#3#4#5% hm, looks like we do a double mathrel
{\begingroup
\def\mtharrfactor{1}%
\def\mtharrextra {0}%
\processaction[#1] % will be sped up
[ \v!none=\def\mtharrfactor{0},
\v!small=\def\mtharrextra{10},
\v!medium=\def\mtharrextra{15},
\v!big=\def\mtharrextra{20},
\v!normal=,
\v!default=,
\v!unknown=\doifnumberelse{#1}{\def\mtharrextra{#1}}\donothing]%
\mathsurround\zeropoint
\muskip0=\thirdoffourarguments #2mu
\muskip2=\fourthoffourarguments #2mu
\muskip4=\firstoffourarguments #2mu
\muskip6=\secondoffourarguments #2mu
\muskip0=\mtharrfactor\muskip0 \advance\muskip0 \mtharrextra mu
\muskip2=\mtharrfactor\muskip2 \advance\muskip2 \mtharrextra mu
\setbox0\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#5\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\setbox4\hbox{#3\displaystyle}% AM: Added displaystyle
\dimen0\wd0
\ifdim\wd4\dimen0 \dimen0\wd4 \fi
\setbox2\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#4\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\ifdim\wd2\dimen0 \dimen0\wd2 \fi
\setbox4\hbox to \dimen0{#3\displaystyle}% AM: added dislaystyle
\mathrel{\mathop{\hbox to
\dimen0{\hss\copy4\hss}}\limits^{\box0}_{\box2}}
\endgroup}
\let\domthxarrsingle\domthxarr
%D Now, for defining overarrows.
\def\definemathoverarrow
{\dotripleargument\dodefinemathoverarrow}
\def\dodefinemathoverarrow[#1][#2][#3]%
{\ifthirdargument
\setvalue{#1}{\dohandlemathoverarrow[#2][#3]}%
\else
\setvalue{#1}{\dohandlemathoverarrow[\zeropoint][#2]}%
\fi}
\def\dohandlemathoverarrow[#1][#2]%
{\mathpalette{\dodohanglemathoverarrow{#1}{#2}}}
% Note: math-pln has \kern-\onepoint, amsmath does not. I keep the
% kern amount as an option. This is useful with overharpoons.
\def\dodohanglemathoverarrow#1#2#3#4%
{\vbox{\ialign{##\crcr
#2#3\crcr
\noalign{\kern#1\nointerlineskip}
[EMAIL PROTECTED]
\protect
\definemathoverarrow [overleftarrow] [\leftarrowfill]
\definemathoverarrow [overrightarrow] [\rightarrowfill]
\definemathoverarrow [overleftrightarrow] [\leftrightarrowfill]
--%-
To Here
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
$\overleftrightarrow{A}$ $\overleftrightarrow{ABC}$
$a_{\overleftrightarrow{A}}$ $b_{\overleftrightarrow{ABC}}$
As an added bonus:
\definemathoverarrow [overtwoheadrightarrow] [\twoheadrightarrowfill]
\definemathoverarrow [overtwoheadleftarrow] [\twoheadleftarrowfill]
\definemathoverarrow [overrightharpoondown] [1pt] [\rightharpoondownfill]
\definemathoverarrow [overrightharpoonup] [\rightharpoonupfill]
\definemathoverarrow [overleftharpoondown] [1pt] [\leftharpoondownfill]
\definemathoverarrow [overleftharpoonup] [\leftharpoonupfill]
$\overtwoheadrightarrow {XYZ}$
$\overtwoheadleftarrow {XYZ}$
Re: [NTG-context] \overleftrightarrow
Mojca Miklavec wrote: But to sum up: I really like your patch, and I vote for its inclusion. (The most annoying problem is stil open though.) don't worry, since Aditya is now mostly responsible for the math stuff in context, the patches will be integrated when he thinks they're ok, unless of course this was a personal patch for you -) Hans - Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com | www.pragma-pod.nl - ___ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___
Re: [NTG-context] \overleftrightarrow
On 6/29/07, Aditya Mahajan wrote:
Actually just adding overleftrightarrow is easy, but better will be an
interface to easily define such commands. So
If not, what can I do so that I can use it?
ConTeXt uses overleftarrow and overrightarrow as defined in plain
tex. This does not work in subscripts.
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
Here is a solution. First we patch math-ext so that arrowfills take a
style.
/.../
Wow! Aditya, thanks a lot! I didn't do any extensive testing, but the
functionality should really end up in the core (including the added
bonus if possible ;).
As an added bonus:
\definemathoverarrow [overtwoheadrightarrow] [\twoheadrightarrowfill]
\definemathoverarrow [overtwoheadleftarrow] [\twoheadleftarrowfill]
\definemathoverarrow [overrightharpoondown] [1pt] [\rightharpoondownfill]
\definemathoverarrow [overrightharpoonup] [\rightharpoonupfill]
\definemathoverarrow [overleftharpoondown] [1pt] [\leftharpoondownfill]
\definemathoverarrow [overleftharpoonup] [\leftharpoonupfill]
$\overtwoheadrightarrow {XYZ}$
$\overtwoheadleftarrow {XYZ}$
$\overrightharpoondown {XYZ}$
$\overrightharpoonup {XYZ}$
$\overleftharpoondown{XYZ}$
$\overleftharpoonup {XYZ}$
There are also underarrows, which will not be too hard to do. I will
patch math-ext with both overarrows and underarrows. I think that
there needs to be some italic correction for the arrow. It is
centered on the math box, but the math box is tilted to the right. Any
way to determine the correct horizontal skip that should be added.
Mojca, I remember that you had some trouble with overharpoons. Does
this take care of that?
\vec is not good for two reasons:
a) often stretchable arrows are needed (vectors both over single
letters and things like {AB} are mixed, and \vec looks really weird in
cases where letters are longer, or when we have combinations of them)
b) vectors should be harpoons (not arrows) according to our conventions.
My old \overrightharpoonup definitions had two other problems:
c) scalability/interfering with style change: you solved exactly that
one in a really nice way - thanks a lot (I did patch it, but it looked
like really ugly code)
d) glyphs themselves and their size (probably only the Polish guys can
help here) - and that's the real problem at the moment
Consider
\def\myvec#1{\overrightharpoonup{#1}}
$(\myvec{\imath},\myvec{\jmath},\myvec{k})$ or $\myvec{\nabla}$,
$\myvec{\sigma}$, $\myvec{r}$, ...
The base size on top of i, j, k, ... is just too long and the harpoon
is also slightly too big.
But to sum up: I really like your patch, and I vote for its inclusion.
(The most annoying problem is stil open though.)
Thanks a lot,
Mojca
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archive : https://foundry.supelec.fr/projects/contextrev/
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Re: [NTG-context] \overleftrightarrow
On Thu, 28 Jun 2007, Jesse Alama wrote:
I'm preparing a geometry course using ConTeXt and am impressed with the
system so far. One thing I need is to do is typeset various geometrical
symbols. It looks like ConTeXt already has the \overleftarrow and
\overrightarrow commands, but one thing I'd like to have is
\overleftrightarrow, for typesetting the symbol customarily used to
denote the line determined by two points. It seems, though, that this
isn't available in ConTeXt, or, at least, it is not available by
default. I tried looking on the contextgarden and google, but didn't
come across anything. Is the \overleftrightarrow command already
available?
Actually just adding overleftrightarrow is easy, but better will be an
interface to easily define such commands. So
If not, what can I do so that I can use it?
ConTeXt uses overleftarrow and overrightarrow as defined in plain
tex. This does not work in subscripts.
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
Here is a solution. First we patch math-ext so that arrowfills take a
style.
\unprotect
\def\mtharrowfill#1#2#3#4#5#6#7#8% AM: Added #8 (for displaystyle)
{$\mathsurround 0pt
\thickmuskip0mu\medmuskip\thickmuskip\thinmuskip\thickmuskip
\relax#8#5%
\mkern-#1mu
\cleaders\hbox{$#8\mkern -#2mu#6\mkern -#3mu$}\hfill
\mkern-#4mu#7$}
%D Now we need to make sure that the extensible arrows do not get
%D affected. So...
\def\domthxarr#1#2#3#4#5% hm, looks like we do a double mathrel
{\begingroup
\def\mtharrfactor{1}%
\def\mtharrextra {0}%
\processaction[#1] % will be sped up
[ \v!none=\def\mtharrfactor{0},
\v!small=\def\mtharrextra{10},
\v!medium=\def\mtharrextra{15},
\v!big=\def\mtharrextra{20},
\v!normal=,
\v!default=,
\v!unknown=\doifnumberelse{#1}{\def\mtharrextra{#1}}\donothing]%
\mathsurround\zeropoint
\muskip0=\thirdoffourarguments #2mu
\muskip2=\fourthoffourarguments #2mu
\muskip4=\firstoffourarguments #2mu
\muskip6=\secondoffourarguments #2mu
\muskip0=\mtharrfactor\muskip0 \advance\muskip0 \mtharrextra mu
\muskip2=\mtharrfactor\muskip2 \advance\muskip2 \mtharrextra mu
\setbox0\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#5\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\setbox4\hbox{#3\displaystyle}% AM: Added displaystyle
\dimen0\wd0
\ifdim\wd4\dimen0 \dimen0\wd4 \fi
\setbox2\hbox{$\scriptstyle
\mkern\muskip4\relax
\mkern\muskip0\relax
#4\relax
\mkern\muskip2\relax
\mkern\muskip6\relax
$}%
\ifdim\wd2\dimen0 \dimen0\wd2 \fi
\setbox4\hbox to \dimen0{#3\displaystyle}% AM: added dislaystyle
\mathrel{\mathop{\hbox to
\dimen0{\hss\copy4\hss}}\limits^{\box0}_{\box2}}
\endgroup}
\let\domthxarrsingle\domthxarr
%D Now, for defining overarrows.
\def\definemathoverarrow
{\dotripleargument\dodefinemathoverarrow}
\def\dodefinemathoverarrow[#1][#2][#3]%
{\ifthirdargument
\setvalue{#1}{\dohandlemathoverarrow[#2][#3]}%
\else
\setvalue{#1}{\dohandlemathoverarrow[\zeropoint][#2]}%
\fi}
\def\dohandlemathoverarrow[#1][#2]%
{\mathpalette{\dodohanglemathoverarrow{#1}{#2}}}
% Note: math-pln has \kern-\onepoint, amsmath does not. I keep the
% kern amount as an option. This is useful with overharpoons.
\def\dodohanglemathoverarrow#1#2#3#4%
{\vbox{\ialign{##\crcr
#2#3\crcr
\noalign{\kern#1\nointerlineskip}
[EMAIL PROTECTED]
\protect
\definemathoverarrow [overleftarrow] [\leftarrowfill]
\definemathoverarrow [overrightarrow] [\rightarrowfill]
\definemathoverarrow [overleftrightarrow] [\leftrightarrowfill]
$\overleftarrow{A}$ $\overleftarrow{ABC}$
$a_{\overleftarrow{A}}$ $b_{\overleftarrow{ABC}}$
$\overleftrightarrow{A}$ $\overleftrightarrow{ABC}$
$a_{\overleftrightarrow{A}}$ $b_{\overleftrightarrow{ABC}}$
As an added bonus:
\definemathoverarrow [overtwoheadrightarrow] [\twoheadrightarrowfill]
\definemathoverarrow [overtwoheadleftarrow] [\twoheadleftarrowfill]
\definemathoverarrow [overrightharpoondown] [1pt] [\rightharpoondownfill]
\definemathoverarrow [overrightharpoonup] [\rightharpoonupfill]
\definemathoverarrow [overleftharpoondown] [1pt] [\leftharpoondownfill]
\definemathoverarrow [overleftharpoonup] [\leftharpoonupfill]
$\overtwoheadrightarrow {XYZ}$
$\overtwoheadleftarrow {XYZ}$
$\overrightharpoondown {XYZ}$
$\overrightharpoonup {XYZ}$
$\overleftharpoondown{XYZ}$
$\overleftharpoonup {XYZ}$
There are also underarrows, which will not be too hard to do. I will
patch math-ext with both overarrows and underarrows. I think that
there needs to be some italic correction for the arrow. It is
centered on the math box, but the math box is
