LaTeX, newcommand, Jupyter markdown cells, CoCalc

LaTeX formulas with newcommand-defined bits in Jupyter markdown cells on CoCalc

This is to illustrate

Two markdown cells with the same bit of math, first not using \newcommand, then using it.

**Cell A**

We denote by $\operatorname{span}(u, v)$ the span of two vectors $u$ and $v$.

**Cell B**
$\newcommand{\span}{\operatorname{span}}$

We denote by $\span(u, v)$ the span of two vectors $u$ and $v$.

Cell A

We denote by $\operatorname{span}(u, v)$ the span of two vectors $u$ and $v$ .

Cell B $\newcommand{\span}{\operatorname{span}}$

We denote by $\span(u, v)$ the span of two vectors $u$ and $v$ .

The formula is text in Cell A but an image in Cell B.
When viewing this Jupyter notebook in one's CoCalc project,
- in Cell A
  - one can select text that includes the formula or part of it
  - this selection can be done character by character
  - the selected text gets highlighted in inverted colors (white on blue)
  - the highlighting applies to the selected part of the formula as well
- in Cell B
  - selecting some text, one can include the whole formula or none of it
  - no way to select part of it, character by character
  - highlighting in inverted colors does not apply to the formula if selected
  - if "denote by span(u,v) the span" is selected, "span(u,v)" stays unhighlighted
If this Jupyter notebook is made public on the CoCalc share server
- in Cell A
  - the formula "span(u,v)" gets rendered
- in Cell B
  - the formula "span(u,v)" is missing

Not really sure exactly what goes on but if I had to guess:

KaTeX renders the formula in Cell A as text but the one in Cell B as an image.
this explains the differences in highlighting
this probably also explains the non-rendering on the CoCalc share server
- maybe the image lives in some hidden directory
- maybe it is not made public when the Jupyter notebook is