I am trying to simplify this boolean expression:

```
F = A B ((A + C')') + B (A C + A' B) + (A + B)(A' + C D)

```

The resultant solution is supposed to be:

```
F = A C D + ('A B) + B C

```

But all I can get is 

```
F = A C D + ('A B) + A B C + B C D

```

Help would be appreciated. 

Checked on [this page](http://tma.main.jp/logic/logic.php?lang=en&type=eq&eq=A%20B%20%28~%28A%20%2B%20~C%29%29%20%2B%20B%20%28A%20C%20%2B%20~A%20B%29%20%2B%20%28A%20%2B%20B%29%28~A%20%2B%20C%20D%29) and it says minified form is what real solution is