I'm currrently attempting to solve the Berkley Pacman project Q2 (https://inst.eecs.berkeley.edu/~cs188/sp19/project2.html), but I'm struggling a bit with the alpha beta pruning part. The project demands flexibility in the number of minimizing layers you can have in a row (to be dynamic with increasing amounts of ghosts), and the project offers an auto-grader which tells you whether your solution is correct. My solution fails this task (my minimax works, but I apparently prune the wrong number of nodes), and the autograder gives me an example which it claims my solution solves inappropriately.
I tried running through this example in paint, and it seems to me that the F-node should be pruneable, since we already know that the minimizing node b1 will never choose an option who's value is above 9 (at least 10 in this case). Am I wrong here?