sS ai_buParser_simplify(AI_BottomUpParser1 parser, AI_BottomUpParser1.Word group, S category, Map<T3<S>, S> simplifications) {
  if (group == null) null;
  L<T3<AI_BottomUpParser1.Word, AI_BottomUpParser1.Word, T3<S>>> groupings = ai_buParser1_reconstructedGroupings2(parser, group, category);
  print("Have " + n2(groupings, "grouping") + " for: " + group.text());
  pnl(groupings);
  for (T3<AI_BottomUpParser1.Word, AI_BottomUpParser1.Word, T3<S>> t : groupings) {
    T3<S> production = t.c;
    S simp = simplifications.get(production);
    if (eqOneOf(simp, "K", "L", "R")) {
      print("Simplifying: " + simp);
      if (eq(simp, "L")) ret ai_buParser_simplify(parser, t.a, production.a, simplifications);
      if (eq(simp, "R")) ret ai_buParser_simplify(parser, t.b, production.b, simplifications);
      
      // K
      //temp tempIndent();
      S l = ai_buParser_simplify(parser, t.a, production.a, simplifications);
      S r = ai_buParser_simplify(parser, t.b, production.b, simplifications);
      ret trim(l + " " + r);
    } else
      print("Unknown simplification for " + t.c + ": " + simp);
  }
  ret group.text;
}