\begin{definition}[Definition:Eigenvector/Real Square Matrix]
Let $\mathbf A$ be a square matrix of order $n$ over $\R$. 
Let $\lambda \in \R$ be an eigenvalue of $\mathbf A$. 
A non-zero vector $\mathbf v \in \R^n$ is an '''eigenvector corresponding to $\lambda$''' {{iff}}: 
:$\mathbf A \mathbf v = \lambda \mathbf v$
\end{definition}