`\newcommand` parsing seems to sometimes glitch out or skip commands

Discordius commented 6 years ago

Ok, I am really quite confused by this and am trying to figure this out, so sorry if this turns out to be some kind of bug in MathJax.

I am trying to parse the following HTML document:

<p>This is some random text</p>
<p>\[\newcommand{\NN}{\mathbb{N}}\]
\[\newcommand{\cL}{\mathcal{L}}\]
\[\newcommand{\RR}{\mathbb{R}}\]
\[\newcommand{\dom}{\mathrm{dom}}\]
\[\newcommand{\Pow}{\mathrm{Pow}}\]
\[\newcommand{\cU}{\mathcal{U}}\]</p>
<h1>The new &quot;truth predicate&quot;</h1>
<p>The &quot;truth predicate&quot; we'll discuss in this post will actually be a real-valued two-argument function, \(\theta : \NN\times\NN\to[0,1]\). Let \(\cL\) be the language of set theory, and let \(\cL_\theta\) be \(\cL\) extended with a single constant symbol, also written \(\theta\) (because this constant symbol will represent the function \(\theta(\cdot,\cdot)\) inside our object language); then the arguments to \(\theta(\cdot,\cdot)\) that we're interested in will be the Gödel numbers of sentences in \(\cL_\theta\). Roughly speaking, the reflection principle for \(\theta(\cdot,\cdot)\) will be as follows: If \(\varphi\) and \(\psi\) are mutually exclusive sentences in \(\cL_\theta\) which satisfy a certain topological condition, then will equal \(0\) if \(\varphi\) is true, will equal \(1\) if \(\psi\) is true, and will be arbitrary otherwise</p>

However, if I do this, then the \cL macro fails to be parsed, and I am getting the following error:

W20180814-21:31:36.355(-7)? (STDERR) Formula \psi contains the following errors:
W20180814-21:31:36.355(-7)? (STDERR)  [ 'TeX parse error: Undefined control sequence \\cL' ]

And now this is where it gets confusing. If I change the order of the first two \newcommands, i.e. change the first few lines to the following:

<p>This is some random text</p>
<p>\[\newcommand{\cL}{\mathcal{L}}\]
\[\newcommand{\NN}{\mathbb{N}}\]
\[\newcommand{\RR}{\mathbb{R}}\]

Then I instead get the error that \NN isn't found.

And even weirder, if I just add a random newcommand to the second line like this:

<p>This is some random text</p>
<p>\[\newcommand{\cL}{\mathcal{L}}\]
\[\newcommand{\asdf}{asdf}\]
\[\newcommand{\NN}{\mathbb{N}}\]
\[\newcommand{\RR}{\mathbb{R}}\]

Then everything works fine and I don't get any errors.

Here is my complete mathjax-node-page setup:

mjpage(html, 
  {format: ["TeX"], displayErrors: true, extensions: "TeX/autoload-all.js"}, 
  {html: true, css: true, useGlobalCache: true}, 
  (html) => {
     resolve(html)
  })