Questions about the formula (2) in the paper

[mathfinder]

Hi, I have read your paper, well done.
The first equation of the second formula in the article.

I checked that this is correct.
sigmoid(f) = p/(p+q) -> f = log(p/q)
But how do you find this solution?

[takerum]

please see this: #3

[mathfinder]

thx for your reply！

And I am not sure why the last item in the (5) is a constant as described in the paper.

[takerum]

oh sorry, that does not mean it's constant w.r.t. x, but w.r.t. y. So the last item is dependent on x.