 Jacobson density theorem

If $V$ is a simple left $R$-module and $D={\mathrm{End}}_R(V{)}^{\mathrm{op}}$, then every prescribed map on a finite $D$-linearly independent subset of $V$ is induced by an element of $R$.

The Jacobson density theorem is a result in functional analysis and algebra that concerns the structure of certain types of algebraic structures known as *algebras*. Specifically, it is often discussed in the context of *topological algebras*, which combine algebraic and topological properties.