Look at every entity in the tree.
If we can reduce this entity, continue looking at its siblings.
Otherwise, recurse and look at its children.
End an iteration once we looked at an entire tree.
If we finish an iteration without finding any reductions, we're done.
Look at every entity in the tree. If we can reduce this entity, continue looking at its siblings. Otherwise, recurse and look at its children. End an iteration once we looked at an entire tree. If we finish an iteration without finding any reductions, we're done.