Simplify kmg.domain/recommendation-ids

As we all know, parentheses are evil. Let's get rid of some of them and make the code more readable!
Unfortunately these two functions not equivalent. This function means that I want to get recommendations which is not completed yet. But (keep completed recs) just keep exactly completed recommendations, which is opposite to what is required. I definitely need to add tests for all domain logic:)
Anyway, thank you for try!
May be there is another way to simplify this?