Why is the IAF-VAE model called "inverse" autoregressive flow (IAF)? [D]

What's so "inverse" about it? I understand section 3 in the paper (Inverse Autoregressive Transformations) but I fail to see how section 4 (Inverse Autoregressive Flow (IAF)) follows from there. Do we choose a specific ordering of latent variables, as we do in section 3?

I'd appreciate it if someone could point me to a blog post that walks you through the details of the IAF-VAE model.

Here is the paper: [https://arxiv.org/pdf/1606.04934.pdf](https://arxiv.org/pdf/1606.04934.pdf)

flow machinelearning paper vae variables