# Multiple Matrix Formatting

I'm wondering if there's a more cleaner/nicer way to write this equation

\begin{document}
\begin{enumerate}[a.)]
\item If $u_i, v_i \in \R$ for $1 \leq i \leq 2$, then
\begin{equation*}
\vec{u} \oplus \vec{v} =
\begin{bmatrix}
u_1\\
u_2
\end{bmatrix}
+
\begin{bmatrix}
v_1\\
v_2
\end{bmatrix}
=
\begin{bmatrix}
u_1 + v_1\\
u_2 + v_2
\end{bmatrix}
\in \R^2.
\end{equation*}
\end{enumerate}
\end{solution}
\end{document}


I have about 9 more entries to type up in this list and I don't want my code to be completely unreadable.

• welcome to tex.se! please make your code compilable! as small complete document beginning with \documentclass{...} and ending with \end{document}. and shortly: your code seems to just fine (beside missing things). – Zarko Aug 30 '17 at 22:36
• In particular, \R is undefined. I suspect you want either \renewcommand{\theenumi}{\alph{enumi})}% or [label=\alph*)] using the enumitem package. – John Kormylo Aug 31 '17 at 1:23

I find the following code quite readable. :-)

As you'll notice, I'm not convinced of the benefits of exaggerated nested indentation amounts; naturally, your views may differ. Observe, in addition, the setting up of a macro called \myvec, to simplify the use of instances of bmatrix environments.

\documentclass{article}
\usepackage{amsmath}  % for 'equation*' and 'bmatrix' environments
\usepackage{amssymb}  % for '\mathbb' macro
\usepackage{enumitem} % to modify enumeration labels
\newcommand\R{\mathbb{R}}
\newcommand\myvec[1]{\begin{bmatrix} #1 \end{bmatrix}}

\begin{document}
\begin{enumerate}[label=\alph*)]
\item If $u_i, v_i \in \R$, $1 \le i \le 2$, then
\begin{equation*}
\vec{u} \oplus \vec{v}
= \myvec{ u_1 \\ u_2 } + \myvec{ v_1 \\ v_2 }
= \myvec{ u_1 + v_1 \\ u_2 + v_2 }
\in \R^2\,.
\end{equation*}
\end{enumerate}
\end{document}

• Exactly what I was looking for. Looks much cleaner. Thanks! – lukas Sep 2 '17 at 0:57