Sub-representation

Definition Let $(\rho ,V)$ be a representation of $G$. A sub-representation of $V$ is a subspace $W\subset V$ which is $G$-invariant, that is $\rho (g)W\subset W$ for all $g\in G$. We denote the sub-representation by$(\rho ,W)$, or just $W$.

Representation, or try the Importer!