Sorry, I proposed unit testing as a real-world formalisation of requirements in an earlier post, and you didn't contradict me. What automated system would you use for this instead?
Automated, huh? There is no replacement for using your brain, and reasoning abstractly about the preconditions and postconditions of program fragments.
So, you write down the formal requirements you have of an operating system (with aggressive auto-updates enabled, or disabled, as the customer chooses) once, on a piece of paper, and hope that they don't change?
Your method seems impractical in the extreme in a commercial team environment.