svoid ai_parseTree_makeWeights(AI_BottomUpParser1 parser, L<WeightedProduction> productions, final Element e) {
  // Descend first
  for (Element child : ai_parseTree_getChildren(parser, productions, e))
    ai_parseTree_makeWeights(parser, productions, child);
    
  // Then calculate this node's weight
  
  if (e instanceof ChoosePart)
    e.weight = avg(collectMaxDouble(e.children, 'weight));
  else if (e instanceof HaveCategory && empty(e.children))
    e.weight = 1.0; // TODO
  else
    e.weight = collectMaxDouble(e.children, 'weight);
    
  ai_Reconstructed r =
    e instanceof ChoosePart ? e/ChoosePart.reconstruction
    : e instanceof HaveCategory ? e/HaveCategory.reconstruction : null;
  if (r != null)
    e.weight *= r.production.weight;
}