# Simple

Main form: *simple*, adjective. Used both descriptively (adding detail) and restrictively (restricting the subject). In sciences, typically used in a binary sense (something is either simple or is not simple), whereas in the social sciences and daily parlance, typically used to describe position on a wider scale.

Related forms: *simplicity* (whether or not something is simple, extent to which something is simple)

Typical use:

- Easy to handle, basic, lacking in complexity. Similar words: easy, basic
- Something that cannot be decomposed, reduced or broken up. Similar words: indecomposable, irreducible.
- Honest, open and straightforward, not deceitful, designing, or guileful. Similar words: straightforward

Opposite words: compound, complex, convoluted, decomposable, reducible.

Derived words: semisimple, quasisimple, pseudosimple.

Learn more about simple

Dictionary definitions: Oxford English Dictionary, Merriam Webster, Wiktionary, The Free Dictionary

Visual Thesaurus: Visual Thesaurus

## Contents

## Mathematics

### In group theory

**Simple group**: A nontrivial group that has only two normal subgroups: the whole group and the trivial subgroup.

Related terms: Almost simple group, quasisimple group, characteristically simple group, simple algebraic group

Term variations: Groupprops:Category:Variations of simplicity

Primary subject wiki entry: Groupprops:Simple group

Also located at: Wikipedia:Simple group, Mathworld:SimpleGroup, Springer Online Reference Works

### In noncommutative ring theory

**Simple ring**: A nonzero unital ring in which the only two-sided ideals are the whole ring and the zero ideal.

Primary subject wiki entry: Noncommutative:Simple ring

### In topology

**Simple space**: A path-connected space with Abelian fundamental group whose induced action on all higher homotopy groups is trivial.

Primary subject wiki entry: Topospaces:Simple space

### In measure theory

**Simple function**: A real-valued or complex-valued function on a measure space that is expressible as a finite linear combination of indicator functions of measurable subsets.

Primary subject wiki entry: Measure:Simple function

Also located at: Wikipedia:Simple function