Hi guys, this is my first time to learn ppl and my question may sound stupid. Much appreciation for any pointers or suggestions!

Throughout the official tutorial, I can’t find simple examples of exact inference on a graph with discrete variables (many have suggested HMM or GMM examples, but you need to know the model and many things like Poutine, AutoDelta to understand the code).

I do find some good discussions here, like

- https://forum.pyro.ai/t/obtain-conditional-probabilities-for-discrete-variables/1236
- https://forum.pyro.ai/t/pyro-for-directed-bayesian-network-inference/1580/4

But I still don’t know how to write my own example (actually I try to modify them but I always fail with errors like “ValueError: Number of einsum subscripts must be equal to the number of operands.” ). For example, I failed to write a simple model including 4 binary variables x1, x2, x3, and z = x1 & x2 & x3 (logical and) and obtain the exact conditional probability P(z|x1=1) (I know this example doesn’t utilize observed samples and deep learning but I just want to know how I can do that).

I am also writing notes with “stupid” examples, and hope that it could help someone with little knowledge about ppl like me.