Else if Statement Wordpress.

Using the ! you are going to get this logic if is not single //anything that is not a home or page will apply this so it will not get to the else.

Using it without the ! will go clear to the else statement if it is not a single or home. Then it will apply the style-sheet of the else the way you have it. If you are seeing your homepage, it is not a single so it will stop there.