They wouldn't. My point was that A⋅B is also hiding a sum across all indices, just like Einstein notation. The sum never changes and is therefore visual/cogniti

They wouldn't. My point was that A⋅B is also hiding a sum across all indices, just like Einstein notation. The sum never changes and is therefore visual/cognitive noise, once you've understood it the first time. The dot product is an abstraction that hides it and makes it implied.