Self-serving FYI: In this comment I summarized Eliezer_Yudkowsky's list of the ways that Newcomb's problem, as stated, constrains a Bayes net.

For the non-link-clickers:

• Must have nodes corresponding to logical uncertainty (Self-explanatory)

• Omega's decision on box B correlates to our decision of which boxes to take (Box decision and Omega decision are d-connected)

• Omega's act lies in the past. (ETA: Since nothing is simultaneous with Omega's act, then knowledge of Omega's act screens off the influence of everything before it; on the Bayes net, Omega's act blocks all paths from the past to future events; only paths originating from future or timeless events can bypass it.)

• Omega's act is not directly influencing us (No causal arrow directly from Omega to us/our choice.)

• We have not found any other property which would screen off this uncertainty even when we inspect our own source code / psychology in advance of knowing our actual decision, and that our computation is the only direct ancestor of our logical output. (Seem to be saying the same thing: arrow from computation directly to logical output.)

• Our computation is the only direct ancestor of our logical output. (Only arrow pointing to our logical output comes from our computation.)