static bool matchWordSequence(O pat, O real, IMatchF matchF, Map map) {
  if (!(pat << WordSequence && real << WordSequence)) false;
  int n = l(pat.l);
  if (n != l(real.l)) false;
  for i to n:
    if (!matchF.get(pat.l.get(i), real.l.get(i), map)) false;
  true;
}