C3 - cycle
- let
such that - select
from - a cycle is defined as:
- in an array:
-
a cycle with
components is called an -cycle -
consider the permutation:
-
this can be presented schematically as:

image: J. Gallian 2020 -
the arrows can be left out, and this can be further simplified as:
-
cycles can be multiplied,
, and the results can be expressed as disjoint cycles -
as function composition is done for right to left, so is cycle multiplication
-
any symbol not contained in a cycle is fixed, ie.
fixes (1) -
conventionally, single element cycles are omitted as they are mapping to themselves, ie.
-
identity permutations can be written as just one cycle, eg.
or -
note: some conventions may also use left to right composition