The arrow for bijective maps
Jose Capco
In mathematical typsetting I am trying to find the bijective mapping arrow
something that looks like this : ">->>"
I couldn't find this in the AMSFonts, anyone who uses this or has seen where I
can find this symbol?
Sincerely,
Jose Capco
Manoj Kummini
> In mathematical typsetting I am trying to find the bijective mapping
> arrow something that looks like this : ">->>"
\usepackage{amssymb}
$\rightarrowtail \hspace{-1.9ex} \twoheadrightarrow$
With regards,
Manoj.
--
Manoj Kummini
Graduate Student, Dept. of Mathematics, The Univ. of Kansas,
Lawrence KS 66045 USA. 38 deg 55 min N, 95 deg 14 min W.
http://www.math.ukans.edu/~kummini/index.html
Scott Pakin
> In mathematical typsetting I am trying to find the bijective mapping arrow
> something that looks like this : ">->>"
> I couldn't find this in the AMSFonts, anyone who uses this or has seen where I
> can find this symbol?
You can look in the Comprehensive LaTeX Symbol List (available from
CTAN) but I don't recall seeing such a symbol there. One possibility
would be to overlap AMS's \rightarrowtail and \twoheadrightarrow symbols,
maybe using something like the following:
\DeclareMathOperator{\bijmap}{%
\rlap{\ensuremath{\rightarrowtail}}%
{\ensuremath{\mkern2mu\twoheadrightarrow}}}
Is that the sort of symbol you're looking for?
-- Scott
Jose Capco
Almost, the former thread suggested that too and I was grateful. But I suppose
if there is no other I will use it
\rightarrowtail \hspace{-1.9ex} \twoheadrightarrow
was suggested. I don't want to be a bad critique, but if there are some
improvements possible. The mapping is just the simple \rightarrow which has an
arrowhead much larger than that of \rightarrowtail or \twoheadrightarrow
the bijective map arrowhead has a size as big as \rightarrow so I made the
following modification
\rightarrowtail \hspace{-1.5ex} \rightarrow
but it also looks funny since the second arrow head is smaller here and the
tail don't suit one of the big arrowhead. Anyway I think I'll use this than try
to find the exact symbol (btw another thing is that there is no line in between
the two arrowheads. roughly it looks like this ">->>"). In case there is a
developer of AMSfonts around, that is one of my suggestion. Its already very
much used in modern math.
Sincerely,
Jose Capco
Herbert Voss
> Almost, the former thread suggested that too and I was grateful. But I suppose
> if there is no other I will use it
> \rightarrowtail \hspace{-1.9ex} \twoheadrightarrow
> was suggested. I don't want to be a bad critique, but if there are some
> improvements possible. The mapping is just the simple \rightarrow which has an
> arrowhead much larger than that of \rightarrowtail or \twoheadrightarrow
> the bijective map arrowhead has a size as big as \rightarrow so I made the
> following modification
> \rightarrowtail \hspace{-1.5ex} \rightarrow
\documentclass[12pt]{article}
\usepackage{amssymb}
\def\mathrlap{\mathpalette\mathrlapinternal}
\def\mathrlapinternal#1#2{%
\rlap{$\mathsurround=0pt#1{#2}$}%
}
\def\bijmap{\ensuremath{%
\mathrlap{\rightarrowtail}\rightarrow}}
\begin{document}
\bijmap \Huge\bijmap
\end{document}
instead of \mathrlap it works in most cases also with \rlap
Herbert
Hendrik Chaltin
Can I catch on?
I have tried already to superpose and set off existing symbols,
but the results are usually poor.
Scott's List (thank you, Scott, very helpful!) p.35
gives a way to make "blackboard" versions
of \alpha etc., <, [ and (.
I would like to make a "blackboard" version of the brace \{.
I tried
$[snip] \makebox[0.05cm]{\{} \! \{ [snip]$
and
$[snip] \textrm{\makebox[0.005cm]{\{}\footnotesize{$|$}} [snip]$
(yes, don't tell me, very poor; in particular the vertical stroke is not centered).
Q1 Does anyone have a more elegant solution?
Q2 Incidentally, why does the vertical stroke turn horizontal if I write
$[snip] \textrm{\makebox[0.005cm]{\{}\footnotesize{|}} [snip]$ ?
As with respect to the original question,
I would indeed also be interested in a good surjective mapping arrow >-->>
(why do you call that a BIJECTIVE mapping arrow?)
and the corresponding injective mapping arrow >>-->.
Specifying sizes in LR boxes seems to yield inconsistent results
(diminishing the size specification will instead INCREASE it, etc.)
(perhaps depending on the typesetting software?
- I use TeXShop on Mac OS 10.3.2).
In particular,
$\rightarrowtail \hspace{-1.9ex} \twoheadrightarrow$
yields in my pdf three arrowheads (not even evenly spaced)
and with
$ \rightarrowtail \hspace{-1.5ex} \rightarrow$
the two arrowheads are too far apart
(and, as you say, their should be no line between them).
Thanks,
HC
Scott Pakin
> I would like to make a "blackboard" version of the brace \{.
I believe the mbboard font includes a blackboard-bold brace. I'd look
there first.
> Q2 Incidentally, why does the vertical stroke turn horizontal if I write
> $[snip] \textrm{\makebox[0.005cm]{\{}\footnotesize{|}} [snip]$ ?
The default OT1 font encoding (used, for example, by Computer Modern)
puts an em-dash in the character position for "|". Knuth apparently
considered "|" a mathematical character and not something one would
need in ordinary text.
-- Scott
Hendrik Chaltin
Your
\def\bijmap ... \bijmap
looks perfect to me.
Any suggestions for "my" "blackboard bold" \{
(cf. my follow-up - which apparently crossed yours)?
Thanks in advance,
HC
Scott Pakin
> Anyway I think I'll use this than try
> to find the exact symbol (btw another thing is that there is no line in between
> the two arrowheads. roughly it looks like this ">->>").
Could you point us to a paper or standalone image on the Web that shows
exactly what you're looking for? ASCII art goes only so far.
-- Scott
Herbert Voss
> Scott's List (thank you, Scott, very helpful!) p.35
> gives a way to make "blackboard" versions
> of \alpha etc., <, [ and (.
> I would like to make a "blackboard" version of the brace \{.
I cannot see such symbols on this page ...
Herbert
Hendrik Chaltin
Thanks.
> I believe the mbboard font includes a blackboard-bold brace.
I am really not at ease with fonts.
The indexes of the LateX Graphics Companion and Kopka and Daly's 4th edition
which I just bought but had no time to browse yet
do not mention any mbboard font.
How do I get and use this font?
Thanks in advance.
(Herbert)
> I cannot see such symbols on this page ...
From the said page :
... mathbol package ... For instance ... is produced by
\mathbb{\Langle\Lbrack\Lparen...}
HC
Herbert Voss
> From the said page :
> ... mathbol package ... For instance ... is produced by
> \mathbb{\Langle\Lbrack\Lparen...}
maybe this helps
Herbert
\documentclass[12pt]{article}
\newcommand\Double[2][2mu]{\ensuremath{\rlap{$#2$}\mkern#1#2}}
\parindent=0pt
\begin{document}
{\Huge\Double{\{}} \Double{\{}
{\Huge\Double{[}} \Double{[} :-) \Double{]}{\Huge\Double{]}}
\Double{\}} {\Huge\Double{\}}}
{\Huge\Double[-4mu]{[}} \Double{[} :-) \Double{]}{\Huge\Double[4mu]{]}}
\end{document}
Scott Pakin
> I am really not at ease with fonts.
> The indexes of the LateX Graphics Companion and Kopka and Daly's 4th edition
> which I just bought but had no time to browse yet
> do not mention any mbboard font.
> How do I get and use this font?
You can get it from CTAN (http://www.ctan.org); do a search and you should
see it.
The UK TeX FAQ contains a wealth of LaTeX information. The FAQ answer
presented at http://www.tex.ac.uk/cgi-bin/texfaq2html?label=instfont should
get you started on installing fonts.
-- Scott