Some time ago, Kedaman posted a question about what possibly could be the use of the Imp operator.
At that time, I couldn't find a use for it, but now it comes in very handy.

I'm writing a program that needs to read the access rights someone has to a file. This person can also be a member of a group that has certain rights. Access rights can be either allowed or denied. The rights denied overrule the rights allowed. So if someone is member of a group with full control over a file, but also a member of a different group with delete rights denied, this person has all rights accept the delete rights.

Now back to the IMP operator.

The allowed and denied rights can be combined to the resulting access rights like this:

Access rights = Not(Allowed Imp Denied)



So thank you kedaman, for pointing me to that operator. I would have never thougth of it, if I didn't read your post.