static ExactTripleIndex exactTripleIndex() {
  ret new ExactTripleIndex;
}

sclass ExactTripleHasher implements Hasher<TripleWeb> {
  public int hashCode(TripleWeb w) { ret tripleHashCodeByContentsIC(w); }
  public bool equals(TripleWeb a, TripleWeb b) { ret tripleEqualsByContentsIC(a, b); }
}

sclass ExactTripleIndex extends CustomCompactHashSet<TripleWeb> {
  *() {
    super(new ExactTripleHasher);
  }
}