adapting IF-formula

Hello everybody. I'm new here. I'm from the Netherlands. I have a problem.
In the attachement you see in colom L a formula with a IF function including a NUMBER.IF function. All the "double" combinations must appear in colom L showed by the word "double". All the single combinations also must appear in colom L showed by the word "Single". The problem is: only the first of the double combination is showed by the word" double". I want the second also is showed by the word "double". How can I achieve that??

Note, I have a dutch version of excel. IF= ALS(dutch) and NUMBER.IF= AANTAL.ALS(dutch)

Thank you for helping me.

greetings.