Solution
= Solution
For jump rate $W(n,r)$ from $n$ to $n+r$, probability enters state $n$ from $n-r$ and leaves it from $n$. The resulting <kramers-Moyal master equation> is
$$
\boxed{\partial_tP(n,t)=\sum_r
[P(n-r,t)W(n-r,r)-P(n,t)W(n,r)].}
$$
= Solution
For jump rate $W(n,r)$ from $n$ to $n+r$, probability enters state $n$ from $n-r$ and leaves it from $n$. The resulting <kramers-Moyal master equation> is
$$
\boxed{\partial_tP(n,t)=\sum_r
[P(n-r,t)W(n-r,r)-P(n,t)W(n,r)].}
$$