Definition:Quasigroup

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Definition

A quasigroup is a magma $\struct {S, \circ}$ which has the Latin square property.

That is, such that $\forall a \in S$, the left and right regular representations $\lambda_a$ and $\rho_a$ are permutations on $S$.

That is:

$\forall a, b \in S: \exists ! x \in S: x \circ a = b$
$\forall a, b \in S: \exists ! y \in S: a \circ y = b$


Left Quasigroup

$\struct {S, \circ}$ is a left quasigroup if and only if:

for all $a \in S$, the left regular representation $\lambda_a$ is a permutation on $S$.

That is:

$\forall a, b \in S: \exists ! x \in S: a \circ x = b$


Right Quasigroup

$\struct {S, \circ}$ is a right quasigroup if and only if:

for all $a \in S$, the right regular representation $\rho_a$ is a permutation on $S$.

That is:

$\forall a, b \in S: \exists ! x \in S: x \circ a = b$


Also see

  • Results about quasigroups can be found here.


Sources