Where can I find proofs in your paper...?

[ita9naiwa]

Hi. I'm Hyunsung Lee. MS at Sungkyunkwan University in South Korea.

I recently read your paper, Doubly Robust Estimator for Ranking Metrics with Post-Click Conversions.
It is really great work. I read to understand it, and then followed your work thoroughly, but I stuck in proving your proposition 3.4.

it first seems quite straightforward with Mcdiarmid inequality, but...
I also checked you uploaded the full version of the paper on the GitHub but cannot find a reference.

How can I derive the result that you made in Propositions?
It's my first time asking for some proof on a paper with its authors, so I apologize (if any) for rude or arrogance.
Any hint or sketch will be very helpful for me.

PS. I hardly believe that you are an undergraduate, even younger than me, and made such great works! It is super awesome..!