static void ai_spec_answerYesNoTriple(S s) {
  T3<S> t = ai_parseTriple(s);
  ret unless t != null && endsWith(t.b, "?");
  S rel = dropLastTrim(t.b);
  if (ai_hasTriple(t.a, rel, t.c)) {
    ai_postTriple("Yes", "answers triple", s);
    ret;
  }
  
  S neg = ai_text("$X", "is negated relation of", rel);
  if (ai_hasTriple(t.a, neg, t.c)) {
    ai_postTriple("No", "answers triple", s);
    ret;
  }    
}