Prove that $\left(\begin{array}{l}n \\ 0\end{array}\right)+\left(\begin{array}{l}n \\ 1\end{array}\right)+\cdots+\left(\begin{array}{c}n \\ n-1\end{array}\right)+\left(\begin{array}{l}n \\ n\end{array}\right)=2^n$, that is, that the sum of the binomial coefficients for any power $n$ is equal to $2^n$.