I guess it depends on whether or not you want your code to read like natural language. The refactored version reads like: Allow access to the site if the user

I guess it depends on whether or not you want your code to read like natural language. The refactored version reads like: Allow access to the site if the user is signed in or has a trusted IP. The original (DeMorgan's applied): Allow access to the site if the user isn't signed out or doesn't have an untrusted IP. It does help to have a good understanding of propositional logic and Boolean algebra, though.