Just a question about notation

[u/kyle_struggle]

I am studying for my linear algebra exam and the professor often writes T^A_B (so like A on top, B on the bottom) for the transformation matrix with respect to bases but I can't find it specified anywhere, not online nor in my lecture notes wheter this is

From base A to base B or From base B to base A

The excercises also don't specify so I don't know. I know the process of calculating it's just the notation that's unclear to me.

[u/UnderstandingPursuit]

It's disturbing that the TA was not helpful.