static Set philosophyBot_allPartsOfLHS(PhilosophyBot1.LogicRule rule) {
  new Set out;
  philosophyBot_allPartsOfLHS_collect(rule.lhs, out);
  O rhs = rule.rhs;
  print("RHS type: " + className(rhs));
  if (rhs cast PhilosophyBot1.LogicRule)
    philosophyBot_allPartsOfLHS_collect(rhs, out);
  ret out;
}

svoid philosophyBot_allPartsOfLHS_collect(O o, Set out) {
  if (!out.add(o)) ret;
  if (o cast PhilosophyBot1.And) {
    philosophyBot_allPartsOfLHS_collect(o.a, out);
    philosophyBot_allPartsOfLHS_collect(o.b, out);
  }
}