static bool je_checkRule(L<JE_CascadeEntry> rule) {
  for (JE_CascadeEntry e : rule) {
    if (eqicOneOf(e.op, "if", "and")) {
      if (e.java) {
        if (!isTrue(safeInterpretedJavaEval(e.tok)))
          false;
      } else {
        L<S> tok = tok_withoutOuterBrackets(e.tok);
        T3<S> t = ai_tripelize(join(tok));
        if (!has(t))
          false;
      }
    } else if (eqic(e.op, "then"))
      break;
    else
      fail("Unsupported operator: " + e.op);
  }
  true;
}