static L<S> ai_postTriple_multi(S a, S b, Collection<S> c) {
  new L<S> webIDs;
  for (S s : unnull(c))
    addIfNotNull(webIDs, ai_postTriple(a, b, s));
  ret webIDs;
}

static L<S> ai_postTriple_multi(Collection<S> a, S b, S c) {
  new L<S> webIDs;
  for (S s : unnull(a))
    addIfNotNull(webIDs, ai_postTriple(s, b, c));
  ret webIDs;
}