static T3<Symbol> ai_webToTriple(Web web) {
  if (web == null) null;
  Collection<WebRelation> l = web_relationObjects(web);
  if (l(l) != 1) null;
  WebRelation r = first(l);
  if (!web_tripelizableNode(r.a)
    || !web_tripelizableNode(r.b)
    || !web_tripelizableNode(r)) null;
  ret t3(web_sym(r.a), web_sym(r), web_sym(r.b));
}