[OS X TeX] Equations in books

[Luis Sequeira]

> On Mon, Sep 28, 2009 at 10:30:53AM -0500, George Gratzer wrote:
>> The equations in my book are numbered as (IV.3), where IV is the  
>> chapter
>> number and 3 means third equation. I would like to drop IV. How do  
>> I do
>> it.
>>
>> I use the book document class with all the ams packages.
>>
>> GG
>
> Did you already try something like
>
> \usepackage{remreset}
>
> \makeatother
> \@removefromreset{chapter}{equation}
> \makeatletter
>
> \renewcommand\theequation{\arabic{equation}}
>
> (not tested)
>
> -- 
> Siep Kroonenberg
>


What I am about to suggest may be an ugly workaround, and can be seen  
to detriment portability. On the other hand, we're talking about a  
book, so I believe there is more leeway in customization.
I found that you can easily customize book.cls to make it more similar  
to amsbook.cls in its numbering of equations. As you may know, in  
amsbook.cls equations are sequentially numbered, whereas in book.cls  
they are numbered within chapters.
Of course, you should never alter the original book.cls, or any other,  
but it is ok to make a copy, under a different name, and customize it.  
In my limited testing, I created a copy of book.cls in my personal tex  
tree (~/Library/texmf/tex/latex), named it 'mybook.cls' and commented  
out just three lines of it (lines 542, 543 and 544):

%\@addtoreset {equation}{chapter}
%\renewcommand\theequation
%  {\ifnum \c at chapter>\z@ \thechapter.\fi \@arabic\c at equation}

(and, of course, used 'mybook' as the \documentclass in a small test  
file, with a few dummy chapters and equations).
This seems to provide the book.cls look, but with equations numbered  
as they would be in amsbook.

HTH

Luis Sequeira