> Eventually, It would be amazing if all the details of math rendering could make it into Unicode.

I'm not sure if I agree with you or not... Generally I'd say I do, but we're going to have a hard time "finding the line". Meaning what counts as "math"? Surely 1 + 1 is, as is ∇×𝐇, and we can start to do things like x⁰. However, what about a graph with nodes and edges (just as an example)? Is that "math"?

One things strikes me about strings of characters... you can select and copy/paste them (at least in my native alphabet of Latin) very reliably. This property is not present with Unicode in general.

It’s not easy to select characters in Arabic and many Vedic languages.

Microsoft published a technical note on using a Unicode linear encoding for math rendering several years back:

http://www.unicode.org/notes/tn28/UTN28-PlainTextMath-v3.pdf

Office apps support it, apparently, as one among many representations for math zones. A blog post on it:

https://blogs.msdn.microsoft.com/murrays/2016/09/07/unicodem...

We need...

  1. A code-point that starts a fraction.    
  2. A code-point that separates the numerator from the denominator.    
  3. A code-point that ends the fraction.    

So the sequence [START]x[SEP]y[END] would be rendered with x above the y with a line separating.

[START][START]x[SEP]y[END][SEP]z[END] would be a fraction with a fraction inside.

The fraction slash (U+2044) was supposed to be a simpler version of that, but it's not very well supported. https://en.wikipedia.org/wiki/Unicode_subscripts_and_supersc...

"All details of math rendering" probably fall squarely into "markup" territory, thus outside Unicode. At least so far any efforts trying to standardize this led to this. Math is generally nothing I'd call plain text.

Should Unicode be able to represent Egyptian Hieroglyphs? The lack of similar facilities for Egyptian is why Unicode is useless for representing hieroglyphs, despite having a goodly number of signs encoded.

Or--dare we dream it?--chemistry notations.