svoid testParse(S s) {
  print("** \* s */ **");
  print();
  Concept parsed = parseToOptions(s);
  print("Parse concept graph size: " + conceptGraphSize(parsed));
  L<Concept> l = unrollOptions(parsed);
  for i over l: {
    Concept x = l.get(i);
    bool prop = properSentence(x);
    print((prop ? "! " : "") + (i+1) + ". " + structureConcept(x));
  }
  print();
}

static Concept parseToOptions(S s) {
  new L<Concept> l;
  parse(s, listCollector(l));
  ret options(l);
}