A typo in equation on Earth-Mover's distance example

Hey, thanks for the great series of blog posts.

I have a question on the example for Earth-Mover's distance.

lilianweng.github.io/posts/2017-08-20-gan/index.html

Line 534 in be66057

    
           <p>If we label the cost to pay to make $P_i$ and $Q_i$ match as $\delta_i$, we would have $\delta_{i+1} = \delta_i + P_i - Q_i$ and in the example:</p>

Shouldn't the equation be $\delta_{i} = \delta_{i - 1} + P_i - Q_i$ in this line?