about the paper symbol

[bringtree]

Hello, I meet some questions, when I read the paper.

In different i^th, I don't know how (W^S_he,h_k) to compute different results. the (W^S_he,h_k) can't find the symbol 'i'.

Waiting for your reply!

[shubham8111]

I have same doubt, how did you do it finally?

[hassyGo]

At best, I guess Equation (3) is wrong, and it should be something like

(h_i)^T W h_k,

and still I am not sure why we need the "sigma". (just a minor comment)