If $A$ is an algebra and $D_1, D_2\in A$ we can define the commutator $$[D_1, D_2]:=D_1\circ D_2-D_2\circ D_1.$$
I'd like to create an analogous notation to sum up things like these:
$$D_1\circ D-D\circ D_2.$$
It must be a notation which makes sense in general.
It seems something silly, but I am going to use this in another context where expressions like this are huge and very frequent so it would be very useful to have such a notation.
Thanks.