Question: I am trying to integrate a version/source control system with my unity project. [This answer](http://answers.unity3d.com/answers/1251608/view.html) directed me towards using source/version control. (I dont know the difference.) 

The answer links to a tutorial which explains creating the repository and pushing it to a remote service. I followed the whole tutorial. But I still don't understand how this integrates with my current projects.

My question is that.

1. how can I do this locally
2. how will this make it possible to revert to previously-saved versions?

Answer: 
This is simple math, the php code does exactly what it looks like it does. Am I missing something?

loop 1: 

```
    $i = 1
    $s = 0 + (2*1 + 5) = 7

```

loop 2: 

```
    $i = 2
    $s = 7 + (2*2 + 5) = 7 + 4 + 5 = 16

```

loop 3: 

```
    $i = 3
    $s = 16 + (2*3 + 5) = 16 + 6 + 5 = 27

```

loop 4: 

```
    $i = 4
    $s = 27 + (2*4 + 5) = 27 + 8 + 5 = 40

```
Using pseudo code:

```
n = 2
a = 5
s = 0

for ( i in { 1...4 } ) {

    s = s + ( ( 2 * i ) + 5 )
}

```

So we have

```
s =  0 + ( ( 2 * 1 ) + 5 ) =  0 +  7 = 7
s =  7 + ( ( 2 * 2 ) + 5 ) =  7 +  9 = 16
s = 16 + ( ( 2 * 3 ) + 5 ) = 16 + 11 = 27
s = 27 + ( ( 2 * 4 ) + 5 ) = 27 + 13 = 40

```