I'm trying to get a typical Latex strikethrough with MathJax in an HTML
export, i.e., \cancel{thing} puts line through "thing". This
<http://docs.mathjax.org/en/latest/tex.html#cancel> tells me how. But I
don't know how to include this MathJax markup in an org file for HTML
export. If I forego MathJax -- i.e., #+OPTIONS: tex:dvipng instead
of #+OPTIONS: tex:t -- \cancel works, but I need to use MathJax. It doesn't
look like org-html-mathjax-options is expandable. . . .LB
