Maschke's theorem

《Cohomologie Locale Des Faisceaux Coherents (Sga 2): Seminaire De Geometrie Algebrique Du Bois Marie 1962 (Documents Mathematiques)》 · 印刷第 7 页 Section 1.2「Semisimple Representations」，Theorem 1.2.1 完整陈述及第 8 页末段首句的定理名称（省略中间内容）

Theorem 1.2.1 (Maschke). Let $V$ be a representation of the finite group $G$ over a field $F$ in which $|G|$ is invertible. Let $W$ be an invariant subspace of $V$. Then there exists an invariant subspace $W_1$ of $V$ such that $V=W\oplus W_1$ as representations. […] We will now relate the property of semisimplicity to the property that appears in Maschke's theorem, namely that every submodule of a module is a direct summand.