static void ai_spec_answerExternalQuestion(S question) {
  S q = unquote(question);
  ai_spec_switcheroo(q);
  S q2 = ai_text(q, "switcheroo", "$X");
  if (q2 == null) ret;
  ai_speculate(q2);
  S a = ai_text("$X", "answers", q2);
  if (a == null) ret;
  
  // Optional switcheroo back
  ai_spec_switcheroo(a);
  S a2 = or(ai_text(a, "switcheroo", "$X"), a);
  
  ai_postTriple(a2, "answers external question", question);
}