Coset/Examples/Symmetric Group on 3 Letters/Cosets of Alternating Subgroup
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Examples of Cosets
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Consider the symmetric group on 3 Letters.
Let $S_3$ denote the set of permutations on $3$ letters.
The symmetric group on $3$ letters is the algebraic structure:
- $\struct {S_3, \circ}$
where $\circ$ denotes composition of mappings.
Let $H \subseteq S_3$ be defined as:
- $H = \set {e, \tuple {1 2 3}, \tuple {1 3 2} }$
The cosets of $H$ are:
\(\ds e H\) | \(=\) | \(\ds \set {e, \tuple {1 2 3}, \tuple {1 3 2} }\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \tuple {1 2 3} H\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \tuple {1 3 2} H\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds H\) |
\(\ds \tuple {1 2} H\) | \(=\) | \(\ds \set {\tuple {1 2}, \tuple {1 2} \tuple {1 2 3}, \tuple {1 2} \tuple {1 3 2} }\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \set {\tuple {1 2}, \tuple {2 3}, \tuple {1 3} }\) |
Sources
- 1965: Seth Warner: Modern Algebra ... (previous) ... (next): Chapter $\text {II}$: New Structures from Old: $\S 11$: Quotient Structures: Exercise $11.5 \ \text{(b)}$