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What does the tilde mean in your Cat/Tail example?
by supercanuck 11y ago
What does the tilde mean in your Cat/Tail example?
- graeme 11y agoOops, that was a convention from LSAT forums. It means "not". I changed the comment to just use "not" instead because it's clearer here, thanks.
- thaumasiotes 11y agoInterestingly, ~ for logical negation is also a convention in C, which I think is more widely known among HN users. I would have predicted (wrongly, obviously) that the LSAT might use the symbol from logic, ¬. Any idea how they chose the tilde?
- infogulch 11y agoMaybe because there's a key for it on almost all keyboards?
- thaumasiotes 11y agoI don't see why the LSAT would care when the SAT, GRE, etc. don't...
- deanmen 11y ago~ on the US keyboard is in the same location as ¬ on the UK keyboard, and ~ is in ASCII. I have seen both in math books, but ~ is even used in some books which were printed before computers.
- thaumasiotes 11y agoHmm, according to the wikipedia article on ~, it's the original negation symbol in logic, and "Modern use has been replacing the tilde with the negation symbol (¬) for this purpose, to avoid confusion with equivalence relations." I wonder when that started.
- graeme 11y agoThe LSAT only has English, no logical symbols are used. The the English in the test often has logical meaning. So when discussing that online, by convention students often use ~ If strikethrough is available, students use that instead quite often.