I'm currently writing an article for school in literate Haskell, which is basically a file format/syntax that's a LaTeX document but for anything written in \begin{code}...\end{code} are codes that could compile into a library. (So something like following)

\begin{document}
Now we'll implement a mapping from $x$ to $x+3$

\begin{code}
f x = x + 3
\end{code}

\end{document}

But if my knowledge is correct, GPLv3 (which is the license I would like to use) is a license for codes, not documents. Which made me think does this meant I'll need to license my work under two licenses? Like GPLv3 (for code) and CC-BY-SA (for documentations)? And if that's the case, what will my LICENSE.txt file's format be like?

Perhaps something like following?

License for code:
(Paste GPL here)

License for others:
(Paste CC-BY-SA here)

P.S. Notice (another complicated part is) that the code parts and documentation parts are all contained within one single TeX/PDF file. Hence licensing on a file-by-file basis won't solve my issue.

I'm currently writing an article for school in literate Haskell, which is basically a file format/syntax that's a LaTeX document but for anything written in \begin{code}...\end{code} is code that could compile into a library. (So something like following)

\begin{document}
Now we'll implement a mapping from $x$ to $x+3$

\begin{code}
f x = x + 3
\end{code}

\end{document}

But if my knowledge is correct, GPLv3 (which is the license I would like to use) is a license for code, not documents. Which made me think does this mean I'll need to license my work under two licenses? Like GPLv3 (for code) and CC-BY-SA (for documentation)? And if that's the case, what will my LICENSE.txt file's format be like?

Perhaps something like following?

License for code:
(Paste GPL here)

License for others:
(Paste CC-BY-SA here)

P.S. Notice (another complicated part is) that the code parts and documentation parts are all contained within one single TeX/PDF file. Hence licensing on a file-by-file basis won't solve my issue.