Theorem CB Change-of-Basis

Suppose that $\vect{v}$ is a vector in the vector space $V$ and $B$ and $C$ are bases of $V$. Then \begin{equation*} \vectrep{C}{\vect{v}}=\cbm{B}{C}\vectrep{B}{\vect{v}} \end{equation*}

Proof
(in context)