Antiassociative Structure of Finite Order

Theorem
Let $n \in \N$ and $n > 2$.

Then there exists an algebraic structure $\left({S, \circ}\right)$ of order $n$ such that $\circ$ is antiassociative on $S$.

Proof
Let $S = \{a_0, \ldots, a_{n-1}\}$

Let $\circ$ be a binary operation defined on $S$ such that:


 * $\forall x \in S: x \circ a_i = a_{(i+1) \bmod \, n}$

Then $\forall j, k, m \in \left[{0 \,.\,.\, n-1}\right]$:

and:

As $n \ge 2$ it follows that:
 * $m+1 \ne m+2 \pmod n$

and so $\forall j, k, m \in \left[{0 \,.\,.\, n-1}\right]$:


 * $\left({a_j \circ a_k}\right) \circ a_m \ne a_j \circ \left({a_k \circ a_m}\right)$

Hence the result.