# Definition:Generator of Module/Unitary

Jump to navigation
Jump to search

## Definition

Let $R$ be a ring with unity.

Let $M$ be a unitary $R$-module.

Let $S \subseteq M$ be a subset.

$S$ is a **generator of $M$** if and only if every element of $M$ is a linear combination of elements of $S$.

## Also known as

A **generator** of a module is also known as a **spanning set**.

Some sources refer to a **generator for** rather than **generator of**. The two terms mean the same.

It can also be said that $S$ **generates $M$ (over $R$)**.

Other terms for $S$ are:

- A
**generating set of $M$ (over $R$)** - A
**generating system of $M$ (over $R$)**

Some sources refer to such an $S$ as a **set of generators of $M$ over $R$** but this terminology is misleading, as it can be interpreted to mean that each of the elements of $S$ is itself a **generator** of $M$ independently of the other elements.

## Also see

## Sources

- 1964: Iain T. Adamson:
*Introduction to Field Theory*... (previous) ... (next): Chapter $\text {I}$: Elementary Definitions: $\S 4$. Vector Spaces - 1998: Yoav Peleg, Reuven Pnini and Elyahu Zaarur:
*Quantum Mechanics*... (previous) ... (next): Chapter $2$: Mathematical Background: $2.2$ Vector Spaces over $C$