Definition:Entropic

Let $$\circ$$ be an operation on a set $$S$$ such that:


 * $$\forall a, b, c, d \in S: \left({a \circ b}\right) \circ \left({c \circ d}\right) = \left({a \circ c}\right) \circ \left({b \circ d}\right)$$

Then $$\circ$$ is entropic.

Entropic Structure
An entropic structure is an algebraic structure $$\left({S, \circ}\right)$$ such that $$\circ$$ is an entropic operation.