[00:29.89]If something hasn't happened If something's not the case If you find data missing Inside your database Then it's time to find an alternative Because negation can be quite informative If there is something that you know is not true Then it's subject to analytic review If X isn't even If Y isn't prime If Z has no factors Then it's counterfactual time If one event occurs Another is precluded From that information A case can be concluded A proof is like a waltz with what is true and what is false Don't just consider what you know but also your fact-fiction ratio If X isn't even If Y isn't prime If Z has no factors Then it's counterfactual time