These have package visibility to test the law that for all Expr, the node they evaluate to is unique
Apply the given rule to the given dag until the graph no longer changes.
apply the rule at the first place that satisfies it, and return from there.
ensure the given literal node is present in the Dag Note: it is important that at each moment, each node has at most one id in the graph.
After applying rules to your Dag, use this method to get the original node type.
Returns 0 if the node is absent, which is true use .
Return the number of nodes that depend on the given Id, TODO we might want to cache these.
This finds the Id[T] in the current graph that is equivalent to the given N[T]
This throws if the node is missing, use find if this is not a logic error in your programming.
Convert a N[T] to a Literal[T, N]