The beta side of the network: a graph of Rete.Network.Node descriptions.

Internal. The compiler walks each production's sorted left hand side in order. It adds one node per condition, under the nodes the previous condition produced. Node 0 is an artificial root, so the graph has a single entry point.

Parents are a list. A disjunction adds each branch as its own chain, and hands the union of the branch terminals to the next condition. So the branches re-converge on it. That is why the compiler never flattens the LHS to disjunctive normal form: whole-LHS DNF costs work exponential in the number of disjunctions, while fanning out per condition costs only linear work.

Sharing requires equality and the same parent set. Equality alone is a correctness bug. In a({:customer, cid}, {:order, cid, amt}) and b({:vendor, cid}, {:order, cid, amt}), the two order conditions are equal, but they sit under different parents. Sharing them would let a :vendor token join a :customer's elements. A terminal keys on the production's identity instead, so two rules with an identical LHS fire independently.

{:or, []} is false, and the compiler builds nothing for a path through one. Otherwise, a keyless condition after a false element would become an entry point the alpha index feeds. An unsatisfiable rule would then fire on every fact. See docs/design/network.md §4.