public boolean sleepIn1(boolean weekday, boolean vacation) {
  if (vacation) {
    return true;
  }
  else { /* NOT vacation */
    if (weekday) {
      return false;
    }
    else {
      return true;
    }
  }
}

public boolean sleepIn2(boolean weekday, boolean vacation) {
  if (vacation) {
    return true;
  }
  else { /* NOT vacation */
    return !weekday;
  }
}

public boolean sleepIn(boolean weekday, boolean vacation) {
  return vacation || !weekday;
}