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Any ideas?

higherOrderFunctions.swift
```/**
For this code challenge, let’s define a math operation as a function that
carries out some work on two integers and returns an integer as well. An
example is the function below, `differenceBetweenNumbers`, which takes two
integers and calculates the difference between the numbers. After calculating,
it returns the difference.
*/

func differenceBetweenNumbers(a: Int, b:Int) -> (Int) {
return a - b
}

func mathOperation (operation: (first: Int, second: Int) -> (Int), firstInt: Int, secondInt: Int ) -> Int {
return operation(a: firstInt, b: secondInt)
}
```

edit the ask question button copied in the code mid editing this is the one I wrote and wouldn't compile:

```func differenceBetweenNumbers(a: Int, b:Int) -> (Int) {
return a - b
}

func mathOperation (mathOperation: (a:Int, b:Int) -> (Int), int1: Int, int2: Int ) -> Int {
let something = mathOperation(a: int1, b: int2)
return something
}

print(mathOperation(differenceBetweenNumbers, int1: 6, int2: 5))
``` PLUS

I know my code was fine and no it was not the same as mine until you edited it. I was trying to tell you that your code was bad because you were trying to return a parameter named "a" and "b" that did not exist in your function signature.

I'm curious as to why you are naming the parameters of the function that is passed in as a parameter for "mathOperation"? I get it you can do it that way, but the question didn't ask for that.

```func mathOperation (operation: (first: Int, second: Int) -> (Int)
```

Why not just submit the code below that does not name the parameters of the function passed in to your function? In addition, the body of your function is suppose to just return the variables passed in, not assign them to a constant that is returned.

```func mathOperation(operation:(Int,Int) -> (Int),a:Int,b:Int) -> Int
{
return operation(a,b)
}
```

Or if you want to stick with your naming conventions......

```func mathOperation (mathOperation: (Int,Int) -> (Int), int1: Int, int2: Int ) -> Int {
return mathOperation(int1, int2)
}
``` PLUS

Your code below will not compile in Xcode. You are passing two parameters into your return statement named "a" and "b", yet they are no where in your function signature.

```func mathOperation (operation: (first: Int, second: Int) -> (Int), firstInt: Int, secondInt: Int ) -> Int {
return operation(a: firstInt, b: secondInt)
}
```

This will.

```func mathOperation (operation: (first: Int, second: Int) -> (Int), firstInt: Int, secondInt: Int ) -> Int {
return operation(first: firstInt, second: secondInt)
}
```

Or you could do a lot less typing and just submit this.

```func mathOperation(operation:(Int,Int) -> (Int),a:Int,b:Int) -> Int
{
return operation(a,b)
}
```

And call it.

```mathOperationTwo(differenceBetweenNumbers, 5, 2)
```