the proof of Shannon entropy

[cecilialeo77]

Hello, I would like to ask a question about the proof of Shannon entropy! In your paper, you wrote: The transformation from pg to pfg can be viewed as a series of such adjustments, which implies that the Shannon entropy of pfg is less than or equal to the Shannon entropy of pg
I don't understand exactly why the conversion from pg to pfg can be viewed as a series of such adjustments, which implies that the Shannon entropy of pfg is less than or equal to the Shannon entropy of pg .
I look forward to your detailed explanation, thank you!