srecord noeq ProbabilisticBinaryMaximumSearch(
  IProbabilisticScheduler scheduler,
  IF1<Double> scoreFunction,
  IVF1<Double> action,
  DoubleRange startRange) {
  double minRadius = 1.0; // when to stop

  // sigmoid function (R to (0; 1))
  swappable double scoreToProbability(double score) {
    ret arctanSigmoid_zeroToOne(score);
  }
  
  swappable double recursionProbability(DoubleRange r) {
    ret zeroOne_double(halfLength(r) <= minRadius);
  }
  
  run { lookAtRange(startRange); }
  
  void lookAtRange(DoubleRange r) {
    double x = center(r);
    double score = scoreFunction.get(x);
    double p = scoreToProbability(score);
    scheduler.at(p, () -> action.get(x));
    double pRec = p * recursionProbability(r);
    scheduler.at(pRec, () -> lookAtRange(lowerHalf(r)));
    scheduler.at(pRec, () -> lookAtRange(upperHalf(r)));
  }
}