There's a dispute amongst the Rishonim how exactly to define what is a lav hanitak leaseh (as Artscroll translates: a negative commandment that is given over for positive rectification). I find the simplest explanation is Rashi to Makkos 14b, that the mitzvah is only possible after breaking some other mitzvah which is prohibited. It's as if it gets activated, and its purpose is to rectify the prohibition that activated it (I'm aware some cases don't fit this last sentence).
One example is according to the Sages, there's a prohibition of taking a mother bird upon her chicks/eggs. If a person did, he has a mitzvah to send away the mother bird, in order to fix the prohibition he broke.
I was wondering if there was a list anywhere (or even if someone would make a comprehensive list here) of all the different cases of such a mitzvah? I know some are a dispute, but I can only think of 4-5 off the top of my head.