function redundancyProp(input, output) {
  var len = output.length;
  for (var i = 0; i < len; i++) {
    for (var j = 0; j < len; j++) {
      if (i === j) {
        continue;
      }

      if (isSubset(output[i], output[j])) {
        return false;
      }
    }
  }
  return true;
}
### 5. No output set is a subset of any other output set

  Generalizes (3) and (4)!