github.com/mathjax/MathJax-src/blob/8565f9da973238e4c9571a86a4bc ... eX.ts#L211C1-L211C33
在findMathInString中，
/**
* Search a string for math delimited by one of the delimiter pairs,
* or by \begin{env}...\end{env}, or \eqref{...}, \ref{...}, \\, or \$.
*
* @param {ProtoItem[]} math The array of proto math items located so far
* @param {number} n The index of the string being searched
* @param {string} text The string being searched
*/
有一行：
這一行是什麼意思？ | 
