def map(s: Set, f: Int => Int): Set = (x: Int) =>  {
    var flag : Boolean = false
    for(i <- -bound to bound) {
      if(s(i) && f(i) == x){
        flag = true
      }
    }
    flag
  }

(-bound to bound) exists {i => s(i) && f(i) == x}

def map(s: Set[Int], f: Int => Int): (Int => Boolean) =
  (x: Int) => {
    (-bound to bound).exists(i => s(i) && f(i) == x)
  }