static ChoosePart ai_parseTree_descendToComposite(PTElement e) {
  /*while (e instanceof ChooseCategory
    || e instanceof HaveCategory
      && (e/HaveCategory.reconstruction == null || e/HaveCategory.reconstruction.b == null)) {*/
  while (e != null && !e instanceof ChoosePart) {
    PTElement e2 = e;
    e = first(e.children); // Choose most likely reconstruction
    //print("Went from " + className(e2) + "(" + e + ") to " + className(e) + " (" + n2(e2.children, "child", "children") + ")");
  }
  ret (ChoosePart) e;
}