Use reduction to establish the undecidability of the each of the decision problems.
The computation of a Turing machine $\mathrm{M}=\left(\mathrm{Q}, \Sigma, \Gamma, \delta, q_0, \mathrm{~F}\right)$ with input $w$ reenters the start state if the machine is in state $q_0$ at any time other than the initiation of the computation. Prove that there is no algorithm that determines whether a Turing machine reenters its start state.