Theorem and proof environment in bookdown rendering as “code” in .pdf output

Question

I'm using bookdown to type up my notes from some of my math courses. I want to use theorems and proofs as described here but I'm having issues with rendering when I actually knit the .pdf file. Basically, the .pdf renders what appears to be code, without actually formatting correctly, as I would be able to do "manually" in LaTeX.

I have tried switching between outputs (both HTML and .pdf knits have the same issue), I've used devtools::install_github('rstudio/bookdown') to install the development version of bookdown, and I've followed the following links, to no avail: here , and here, though this is a simple error that I'm certain I took care of .

Here is my header:

--- 
title: "title"
author: author
date: '`r format(Sys.Date(), format="%B %d, %Y")`'
output:
  pdf_document:
    fig_caption: yes
    toc: yes
  html_document:
    toc: yes
 description: description
 documentclass: book
 header-includes:
- \usepackage{amssymb}
- \usepackage{amsmath}
- \usepackage{amsthm}
- \usepackage{tikz}
- \usepackage{hyperref}
- \usepackage{float}
- \usepackage{multirow}
link-citations: yes
numbersections: yes
bibliography: book.bib
site: bookdown::bookdown_site
biblio-style: apalike
---

And here is what I've tried

```{proposition}

If $X$ is a random variable and $X = c$, where $c \in [-\infty, \infty]$, then $\mathbb{E}[X] = c$.
```

```{proof}

Define a function $f(x)$ s.t. $f(x) = \begin{cases} 1 &\mbox{if } x = c \\ 0 &\mbox{otherwise} \end{cases}.$

```

Edit: I've also tried directly pasting in the examples here with no luck.

As mentioned earlier, I'm expecting something like Theorem 2.1 on this page , but instead it prints what appears to look like code. I've uploaded an example here , and the same thing happens if I switch to HTML.

Answer 1

As @Yihui Xie pointed out, I was using the incorrect output format. That link actually helped me figure out that I did not want a long, single document in the first place and figure out the appropriate book formatting, but I checked the output following the instructions on that page, as well as by creating the proper formatting and both work now. Thank you!