[texhax] The undertilde package.

[Rolf Turner]

On 10/05/14 11:07, Bob Tennent wrote:
>   >|> I'm wrong. It is undertilde.tex. Why did you think it was an sty
>   >|> file?
>   >|
>   >|Well ... I guess the short answer is I didn't.  I just wanted to use
>   >|\utilde, found it was provided by the package "undertilde" and so put
>   >|\usepackage{undertilde} in my preamble.  (Isn't that what one usually
>   >|does in respect of packages?)
>   >|
>   >|But this produced the error "package undertilde not found" (or words to
>   >|that effect).
>   >|
>   >|There *is* a .sty file in the undertilde package which I downloaded from
>   >|CRAN and managed to install.  After I installed it, there was no longer
>   >|any problem with \usepackage{undertilde}.
>   >|
>   >|So I am kind of bewildered as to what you are driving at.  Can you
>   >|please elaborate?  What *should* I have done to get access to the
>   >|\utilde command (without having to install "undertilde" by hand as it
>   >|were.  And why wasn't undertilde.sty available from the get-go from my
>   >|installation of Texlive 2013?
>
> If you use
>
> \usepackage{xxx}
>
> LaTeX expects to find xxx.sty. But undertilde in TeXLive is a
> "generic" package, usable with Plain TeX, so it's been named
> undertilde.tex and it's loaded by using
>
> \input{undertilde}
>
> The undertilde.tex in TeXLive is likely from
>
> http://www.ctan.org/pkg/undertilde-gen
>
> The undertilde package available at
>
> http://www.ctan.org/pkg/undertilde
>
> seems to be different.

OK.  Thanks.  It's  bit confusing, but I think that I now have it sorted.

Looking again at some sources on the web about the undertilde package I 
noticed a comment (which I didn't notice yesterday; sigh!):

> Added by the crowd: This package is not part of TeX Live, so you may
> have to install it manually.

That clears up one mystification.

It would also be as well to note that the file undertilde.tex provides a 
command ***\undertilde*** and *not* the command \utilde.  (Another 
source of possible confusion.)  If one wants the briefer form one
can do: \newcommand{\utilde}{\undertilde} after \input{undertilde}.
This seems to work.

Thanks again.

cheers,

Rolf Turner