So, I have three expressions P Q and R, and their negatives. I want to add them together in all possible ways, like so:

P Q R

P Q -R

P -Q -R

-P Q R

-P Q -R

-P -Q -R

Order doesn't really matter since you're adding the terms together, I know this. I just want to make sure I have completely exhausted all possibilities, as well as know how I did. I have very little discrete math knowledge.

Thanks