| ▲ | danabramov 2 hours ago |
| I made a picture, hope this helps: https://excalidraw.com/#json=zfKWWn1h7GzdFca6RDdXl,plr_WeaCt... Sorry it was confusing. Edit: the picture is now edited into the article. |
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| ▲ | howunfortunate 2 hours ago | parent | next [-] |
| This would make a lot more sense to me if "nothing" and "nothing" were instead "-inf" and "+inf" Some other comments clarify that "nothing" is more accurately "the empty set". This is helpful because at first I wrongly synonomized "nothing" with zero. But now I get tripped up on the "between" language. Maybe it's a lack of background in sets, but I don't know what "between" implies for an integer (zero) and a set (the empty set). |
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| ▲ | danabramov 2 hours ago | parent | next [-] | | I didn't want to introduce the notion of infinity because there are actual "infinite numbers" on the surreal number line. I've kind of tried to have both the simplicity of set-theoretic definition and the intuition of the number line, and slightly bungled the exposition. I hope the newly added diagram helps. My favorite intro to surreal numbers is https://www.infinitelymore.xyz/p/surreal-numbers, but it is behind a registration wall. | |
| ▲ | mcintyre1994 2 hours ago | parent | prev [-] | | I'm not a mathematician and "nothing" doesn't really make sense for me either. But I guess the problem with inf might be that it'd be strange to get +2 as the next thing between +1 and +inf, while getting +1.5 between +1 and +2. | | |
| ▲ | danabramov 2 hours ago | parent [-] | | It's more that surreal numbers already include infinities like ω, ω + 1, and so on, so "inf" felt like a concept I want to avoid. The actual description is set-theoretic and uses empty sets there ("nothing to the left", "nothing to the right") so I took that a bit too literally. |
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| ▲ | beingforthebene 2 hours ago | parent | prev [-] |
| Wow thanks. I'm a mathematician and also got lost at the step. This illustration makes the construction much more clear. The text isn't really describing this process well |
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