I am really new to cryptography and I have asked a similar question which is about Decisional Diffie-Hellman assumption (What's the meaning of asterisk and PPT in this paper?) and it is already kind of difficult to me.
But this paper Practical Secure Aggregation for Privacy-Preserving Machine Learning (https://eprint.iacr.org/2017/281.pdf) proposes a Two Oracle Diffie-Hellman assumption, which is even more difficult to understand.
Could anyone please tell me bow the oracle function is used in the adversary M? I don't even really understand what the oracle is here.