You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
3/3 combinatorial calculation became impossible, just switch to a topological one. Or geometrize, etc., and you'd be guaranteed to get the right answer to your original question. Hope this helps? The idea became so useful it took off like wildfire, see: https://en.wikipedia.org/wiki/Timeline_of_category_theory_and_related_mathematics …
