[texhax] Oblique cancellation with plain TeX

[Reinhard Kotucha]

On 2019-01-02 at 20:02:28 +0000, Rodolfo Medina wrote:

 > Hi all.
 > 
 > In internet I couldn't find a solution for plain TeX (cancellation of
 > mathematical text with diagonal line over it).  I found this suggestion:
 > 
 > \newbox\TestBox
 > \def\Remove #1 {\setbox\TestBox=\hbox{$#1$}%
 >         \leavevmode\rlap{\vrule height 2.5pt depth-1.75pt width\wd\TestBox}%
 >         \box\TestBox\ }
 > 
 > coming from Barbara Beeton (thanks, Barbara...!) that produces an
 > horizontal line instead.
 > 
 > Please help whoever can.

Does TikZ/PGF provide what you need?

  texdoc pgfmanual

Section 2.2.2 on page 30 explains how to use it with plain TeX.

Other approaches are thinkable:

The LaTeX graphicx package provides a command \rotatebox which
certainly does exactly what you need.  See

  texdoc grfguide

I vaguely remember that there is a wrapper script which allows you to
run LaTeX's graphicx package with plain TeX.  Unfortunately I don't
remember its name.

Did you ever have a look at eplain?  According to the manual, the
LaTeX grahicx package is supported already.

  texdoc eplain

I assume that eplain is just an extension of plain TeX and thus
migration is easy.

I also have a few low-level solutions for plain TeX in my mind but I
really can't recommend them because the amount of time we have to
invest is inacceptable.

Please check first whether you can use an existing package.  IMO the 
\rotatebox command of the LaTeX graphicx package is most promising.

Regards,
  Reinhard

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