 
 // SECTION 1.1.6
 
-func abs1(x:Int) -> Int {
+func abs1(x:Double) -> Double {
     if x > 0 {
         return x
     }else if x == 0 {

    }
}

func abs2(x:Int) -> Int{
    if x < 0 {
        return -x
    }else{

    }
}

func abs3(x:Double) -> Double{
    if x < 0 {
        return -x
    }else{
