## McCleary User’s Guide to Spectral Sequences (Errata)

(pg 455) When an element $u\in H_{n-1}(X)$ satisfies $ru=0$, then, by exactness, there is an element $\mathbf{\bar{u}\in H_n}(X;\mathbb{Z}/r\mathbb{Z})$ with $\partial(\bar{u})=u$. Should be $H_n$ instead of $H_{n+1}$.

(pg 458) The first differential is given by $d^1=\boxed{{\text{red}_p}_*\circ\partial}=\beta$. The order in the printed version is incorrect. Note that the first differential should be $d^1=j\circ k$ for the exact couple.