What is the name of the following statistical / informational interaction:
given A, I know exactly what B is. given B, I know to some extent what A is.
I'm not looking for a probability but rather something like correlation. Something that tells me that I don't need to include B as a feature when A is already a feature. A correlation heatmap wouldn't give me this information, but there must be some computation that tells me "Don't include B, it's worthless."
To give some intuition: A could be an item_id and B an item_category.
Or am I wrong? Is it not worthless at all?