static void ai_spec_analyzeLitList(S s) {
  if (!startsWithAndEndsWith(s, "[", "]")) ret;
  L l = cast safeUnstructure_nullAndPrintShortOnError(s);
  if (l == null) ret;
  post(s, "is a list with length", l(l));
  for i over l:
    post(structure(l.get(i)), "is element " + (i+1) + " in", s);
}