Motivation
In the past, I used double dollar signs $$
to enclose block
equations. As a result, readers couldn’t see them in Firefox.
How can these missing parts be put back to the RSS feeds?
Method
I didn’t know how to use
 typeset curly brackets
{}
using MathJax without using$$
to surround the brackets. If only one$
was used, then it would fail. For example,$\{a_k\}$
wouldn’t work.  inline display mode for summation, limit, etc.
\[
and\]
to surround block equations in Octopress.
Now, I know that kramdown parses the Markdown source code for a post
before MathJax does. Therefore, to mean a backslash ‘\’, one
needs to “double the effort”. (i.e. use \\{a_k\\}
for $\{a_k\}$)
Moreover, I have to use backslash ‘\’ to escape askterisks *
and
underscores _
.
Before I upgraded to Ruby 2 and updated my Octopress source code^{1},
$\displaystyle \lim_{k \to \infty} \frac{1}{k} = 0$
didn’t work.
Now, I can insert inline display equations like
$\displaystyle \lim_{k \to \infty} \frac{1}{k} = 0$.
With reference to an example on the MathJax CDN, I’ve learnt to use
begin{equation}
just like what $\rm \LaTeX$ users do.^{2} When
using it, there’s no need to use $$
to surround it.
Viewing MathJaxLocal.js
on DrZ.ac, I know why I couldn’t
use \[
for a block equation—I didn’t add it to the corresponding
list of delimiters in displayMath
. Actually, at that line, the
whitespace character between two square brackets [
aren’t
necessary.^{3}
While editing a multiline block equation in a post about the Contraction Mapping Principle, I encountered a technical problem: there’s no newline character in the equation. I could just see one very long line. To see how the code was interpreted, I made a screenshot of Firefox before MathJax loaded.
It was evident that putting four backslashes at the end of lines for a
line break wasn’t enough. Therefore, I put two more backslashes
there. This time, the page for an individual post was OK, but the
contents in the blog index page and those under folder /posts/
wasn’t. I viewed the “$\rm \TeX$ Commands” from the popup menu, and
saw that in the page for an individual post, two backslashes were
found; at /posts/*
and the blog index page, only one backslash was
found.
By trial, I finally used eight backslashes in the Markdown source files for a post for a line break.
Result
The source code for a block equation can now be seen in RSS feeds.

See Updated Octopress Source Code in Blog 1 for details. ↩

View the source of A Test of Equation Numbering for details. ↩

See $\rm \TeX$ and $\rm \LaTeX$ math delimiters in MathJax Documentation for details. ↩