static Set philosophyBot_allPartsOfLHS(PhilosophyBot1.LogicRule rule) {
  new Set out;
  philosophyBot_allPartsOfLHS_collect(rule, out);
  ret out;
}

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