Antoine de Scorraille comments on Latent Variables and Model Mis-Specification

[Antoine de Scorraille]

Find $\theta$ to maximize the predictive accuracy on the observed data, ${\sum }_{i=1}^{z}log{p}_{\theta }(y_i,x_i)$, where $p_{\theta }\left(y_i|x_i\right)={\sum }_z{p}_{\theta }(y_i,z|x_i)$. Call the result ${\theta }_0$.

Isn’t the z in the sum on the left a typo? I think it should be n