Square map is endomorphism not implies abelian for loop
Statement
It is possible to have a loop in which the square map (where </math>x^2</math> is the product of with itself) is an endomorphism but where is not a commutative loop, i.e., there exist such that .
Proof
Further information: loop of order five and exponent two
We can construct an example non-abelian loop that has order five and where every element squares to the identity. Clearly, here, the square map is an endomorphism. The loop has the following multiplication table:
| 1 | 2 | 3 | 4 | 5 | |
|---|---|---|---|---|---|
| 1 | 1 | 2 | 3 | 4 | 5 |
| 2 | 2 | 1 | 4 | 5 | 3 |
| 3 | 3 | 5 | 1 | 2 | 4 |
| 4 | 4 | 3 | 5 | 1 | 2 |
| 5 | 5 | 4 | 2 | 3 | 1 |