// t3(in, out, positive example)
static LT3<S, S, Bool> parseExamplesAndAntiExamples(S text) {
  new LT3<S, S, Bool> out;
  for (S s : tlft(text)) {
    LS tok = javaTok(s);
    int i = indexOfSubList(tok, splitAtDoubleArrow_tok());
    if (i < 0) continue;
    bool pos = true;
    S rhs = joinSubList(tok, i+4), lhs;
    if (eqGet(tok, i-1, "") && eqGet(tok, i-2, "!")) {
      pos = false;
      lhs = joinSubList(tok, 0, i-3);
    } else
      lhs = joinSubList(tok, 0, i-1);
    out.add(t3(lhs, rhs, pos));
  }
  ret out;
}

Began life as a copy of #1014190