Word (Abstract Algebra)/Examples

Examples of Words in the Context of Abstract Algebra

Set with $2$ Elements

Let $G$ be a group.

Let $X \subseteq G$ be a subset of $G$ such that $X = \set {a, b}$.

Then some of the elements of the set of words $\map W S$ of $G$ are:

$a, b, a b, b a, a b a, b a b, a^{-1} b, b a^{-1}, a b^{-1}, b^{-1} a, a b^{-1}, a^{-1} b^{-1}, a^{-1} b^{-1} a, \ldots$

Symmetric Group on $3$ Letters

Let $S_3$ denote the Symmetric Group on 3 Letters, whose Cayley table is given as:

$\begin{array}{c|cccccc}\circ & e & (123) & (132) & (23) & (13) & (12) \\ \hline e & e & (123) & (132) & (23) & (13) & (12) \\ (123) & (123) & (132) & e & (13) & (12) & (23) \\ (132) & (132) & e & (123) & (12) & (23) & (13) \\ (23) & (23) & (12) & (13) & e & (132) & (123) \\ (13) & (13) & (23) & (12) & (123) & e & (132) \\ (12) & (12) & (13) & (23) & (132) & (123) & e \\ \end{array}$

Consider the subset $\set {\tuple {1 2}, \tuple {132} }$ of $S_3$.

Then some of the elements of the set of words of $\set {\tuple {1 2}, \tuple {132} }$ are:

$\tuple {123}^2, \tuple {123}^{-1} \tuple {1 2}^2, \tuple {123} \tuple {1 2} \tuple {123}^{-1} \tuple {1 2}^{-1}, \ldots$