Permutations, cycles and order
The bijections of an n-element set form Sₙ under composition, with n! elements.
Key knowledge
The bijections of an n-element set form Sₙ under composition, with n! elements. Each permutation decomposes into disjoint cycles, unique up to cycle order and cyclic starting notation; its order is the least common multiple of the cycle lengths. A k-cycle is a product of k−1 transpositions.
Conditions and scope
- n≥1; composition here applies the rightmost permutation first.
- Include fixed-point 1-cycles when specifying a cycle type on the whole set.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Definitions 5.1/5.5–5.7 and Lemmas 5.4/5.9–5.10.
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Entry details
Permanent link to this entry ↗- Record identity
- math-permutation-cycle-methods
- Revision
- university-core.1
- Structured reference record
- University core expansion