     func toString(s: FuncSet) -> String {
         
         let array = Array(-self.bound ... self.bound).filter { self.contains(s, elem: $0) }
-        let string =
-        array.reduce("", combine: { result, item in
-            result + ", \(item)"
-        })
+        let string = array.map { (g) in return "\(g)" }.joinWithSeparator(", ")
         return string
     }
     

            }
            else {
                return iter(a + 1)
//                return false
            }
        }
        return iter((-1)*bound)

    */
    
    func forall(s: FuncSet, p: FuncSetIndication) -> Bool {
        print("s has elements: \(self.toString(s))")
//        var iter: (Int) -> (Bool) = { _ in false }
//        iter = {
//            a in
