Oliver Sourbut comments on Linear Algebra Done Right, Axler

[Oliver Sourbut]

We call a subspace $S\subset V$ invariant under $f\in L\left(V\right)$ if, for all $\overrightarrow{s}\in S$,

$$f\left(\overrightarrow{s}\right)=\overrightarrow{s}$$

should read

$$f\left(\overrightarrow{s}\right)\in S$$