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.