[texhax] Oblique cancellation with plain TeX

[James Diamond]

On Fri, Jan  4, 2019 at 20:51 (+0000), Barbara Beeton wrote:

> James Diamond has added to this interchange:

>> On Fri, Jan  4, 2019 at 19:14 (+0000), Rodolfo Medina wrote:

>>> Philip Taylor <P.Taylor at Rhul.Ac.Uk> writes:

>>>> Maybe if you were to post a GIF/PNG/JPG/PDF of the effect you are trying to
>>>> create, we non-mathematicians might be better placed to help you ...


>>> The following is a simple example: to be processed with simply `latex file'.  I
>>> want the same but with plain TeX...  Thanks,

>>> Rodolfo

>>> \documentclass[preview,border=12pt,varwidth]{standalone}
>>> \usepackage{cancel}
>>> \begin{document}
>>> \abovedisplayskip=0pt
>>> \[
>>> \frac{a\cancel{b}}{\cancel{b}}=a
>>> \]
>>> \end{document}

>> What is wrong with

>> $$ {a\rlap{$b$}/ \over \rlap{$b$}/} = a$$

>> (Aside from the fact that if $b = 0$ then Bad Things are happening?)

> maybe it would be better to have the slash lapped over the target?

Hi Barbara,

I tried both and they looked identical on my screen.  In one test.
But as the next message in my inbox says, it wasn't the solution
to the general problem.


Cheers.
                                Jim