case theme.math.use
  when 'mathjax'
    if theme.math.per_page
      if is_post() || is_page()
        include ./mathjax.pug
    else
      if page.mathjax
        include ./mathjax.pug

  when 'katex'
    if theme.math.per_page
      if is_post() || is_page()
        include ./katex.pug
    else
      if page.katex
        include ./katex.pug

if theme.mermaid.enable
  include ./mermaid.pug