Chapter 17: xy-pic
https://bookdown.org/yihui/rmarkdown-cookbook/install-latex-pkgs.html
tinytex::install_tinytex()
17.1 pure LaTeX equation environment not rendering xy-pic in HTML
the following xymatrix from LaTeX package xy for xy-pic is not shown or rendered in HTML:
$\LaTeX$
can only be used in HTML, not PDF
\[ \require{xy} \xymatrix{U\ar[ddr]_{\psi}\ar[drr]^{\varphi}\ar[dr]|-{(x,y)}\\ & X\times_{Z}Y\ar[d]^{q}\ar[r]_{p} & X\ar[d]_{f}\\ & Y\ar[r]^{g} & Z } \]
17.2 R figure knit with TikZ engine
https://bookdown.org/yihui/rmarkdown-cookbook/html-scroll.html
https://tex.stackexchange.com/questions/669083/how-can-i-draw-the-following-commutative-diagram
![xy-pic or xymatrix](202401311126-LaTeX-xypic_files/figure-html/unnamed-chunk-3-1.png)
Fig. 17.1: xy-pic or xymatrix
![tikz-cd](202401311126-LaTeX-xypic_files/figure-html/unnamed-chunk-4-1.png)
Fig. 17.2: tikz-cd