svoid ai_parseTree_makeWeights(AI_BottomUpParser1 parser, L<WeightedProduction> productions, final PTElement e) {
  // Descend first
  for (PTElement 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(first(e.children).weight, second(e.children).weight);
  else if (e instanceof HaveCategory && empty(e.children))
    e.weight = or(ai_getWordToCategoryWeight(e.text, e/HaveCategory.category, 1.0);
  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;
}