# [pdftex] Automatic custom equation numbers, hyperref and \ref*

Victor Ivrii vivrii at gmail.com
Wed Feb 22 14:35:29 CET 2006

On 2/21/06, Heiko Oberdiek <oberdiek at uni-freiburg.de> wrote:

HO > > > I wouldn't use equation and eqnarray with amsmath. Because of
HO > > > compatibility issues they aren't too well supported.

VI > > Ouch! What about multline, align and split?

HO > Use amsmath environment with amsmath.
>
>
HO > eqnarray also have problems with spacing that are not fixed
HO > even in LaTeX because of compatibility. Also the amsmath
HO > environments are much more powerful than eqnarray. A substitution
HO > should not be too difficult.

Now I am confused. I know that eqnarray is not amsmath endorsed
environment [and I neither use it nor referred to it], but according
to amsmath documentation "amsldoc.pdf"

equation equation* align align* gather gather* flalign flalign*
multline multline* alignat alignat* split

are.

Now, I discovered that my statement is partially correct (I was wrong

%%%
% and exactly the same is true for multline, align, gather 1+1=2 \label{A}

blah-blah-blah

% and exactly the same is true for multline, align, gather
1+2=3
\tag*{(\ref*{A})\textsuperscript{\textasteriskcentered}} % As you suggested
% but the same exactly happens with $(\ref*{A})^*$ and actually amsmath
% documentation contains examples with mathexpressions inside of \tag*
\label{B}
\end{equation

Blah-Blah-Blah.

\ref*{B} prints fine and creates no link and does not suppose to
\ref{B}   prints fine and creates a link to equation with \label{B}
and this is correct too (and it answers my original question; I was
confused by \pkg{showkeys}

On the other hand, if in \tag*  I replace \ref* by \ref then

link from equation number in \label{B} to equation with \label{A} is created
which is correct and could be useful since logically the second
equation is a variant of the first one and one could want to compare

\ref*{B} prints fine and creates a strange link

\ref{B} creates a bloody mess of three nested links

Remark:   with \pkg{showkeys} \ref* is broken which is a mini-minor issue)

>
VI > > PS In completely different topic and in the response to the third
VI > > person you mentioned attachfile2. I am rather interested in it
>
HO > In the next days I will upload and update packages of mine.
HO > I haven't not yet decided how to proceed with the attachfile2 stuff.

Looking forward! Thanks a lot
>
> Yours sincerely
>   Heiko <oberdiek at uni-freiburg.de>
> --

Best
Victor
>

--
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Victor Ivrii, Department of Mathematics, University of Toronto