Let $\{X(t), t \geq 0\}$ be a Poisson process with parameter $\alpha$. For a fixed $t>0$ define $\delta(t)$ to be the distance from $t$ to the last jump before $t$ if there is one, and to be $t$ otherwise. Define $\delta^{\prime}(t)$ to be the distance from $t$ to the next jump after $t$. Find the distributions of $\delta(t)$ and $\delta^{\prime}(t)$. [Hint: if $u<t, P\{\delta(t)>u\}=P\{N(t-u, t)=0\} ;$ for all $u>0$, $\left.P\left\{\delta^{\prime}(t)>u\right\}=P\{N(t, t+u)=0\} .\right]$