Typst: superscript text like 1st/2nd needs quotes, not LaTeX braces

In Typst math, $1^{st}$ renders literal braces, because {} are not grouping in Typst math. Use a string for upright text in the superscript: $1^"st", 2^"nd", 3^"rd"$. Use parentheses for grouping math: $x^(n+1)$. In markup outside math, 1#super[st] also works. Related gotchas from the same session: -> gives a right arrow in math (or #sym.arrow.r outside), and i' works for a prime with no need for i^'.