Definition:Parity of Permutation

Definition
Let $S_n$ denote the symmetric group on $n$ letters.

Let $\pi \in S_n$, that is, let $\pi$ be a permutation of $S_n$.

The parity of $\pi$ is defined as:


 * Parity of $\pi = \begin{cases}

\mathrm {Even} & : \map \sgn \pi = 1 \\ \mathrm {Odd} & : \map \sgn \pi = -1 \end{cases}$

where $\map \sgn \pi$ denotes the sign of $\pi$.

Also defined as
Some sources define the parity of a permutation as defines its sign: that is, as $1$ and $-1$.

Also see

 * Definition:Parity Group


 * Parity Group is Group
 * Parity Function is Homomorphism